Connection arrangement with plastic pipe and metallic connector

Abstract

The invention relates to a connection arrangement (10) comprising a plastic tube (20) and a metallic connecting piece (30) for producing a fluid-conducting connection of the tube (10) with a further component, wherein an end section (21) of the tube (20) is pushed onto a nozzle (31) of the connecting piece (30) and is pressed onto the nozzle (31) in a sealing manner by means of a metallic retaining ring (40).

Description

The present invention relates to a connection arrangement containing a pipe and a connection piece having the features of claim 1.More particularly, the invention relates to the connection of a fluid-carrying rigid plastic pipe to a connector for establishing a fluid-conducting connection of the pipe to a further component, such as a further pipe, a tank, a heat exchanger or another fluid-carrying device. Such a connecting piece can also be referred to as a fitting.If both the tube and the connecting piece are made of plastic and are fastened to one another in a fluid-tight manner in connection arrangements of this type, the creep of the material over time leads to a loss of the sealing effect. For this reason, solutions have become established in which the connecting piece is made of metal. Known connections between plastic tubes and metallic connecting pieces are usually glued. Such solutions complicate the manufacturing process, since the adhesive has to be applied and cured precisely. This requires a fixed mounting of the components over a longer time under controlled temperature conditions. Moreover, known adhesives cannot be permanently used at elevated temperature. Alternatively, the fluid-tight connection is ensured by means of introduced rubber seals. The use of an additional sealing element in a connection which is not sufficiently tight per se alone is not capable of permanently reducing the risk of leakage.It is the object of the present invention to provide a connection arrangement of the type mentioned at the beginning, with which a long-lived fluid-tight connection between pipe and connecting piece can be achieved in a manner which is simple to produce. In particular, the connection arrangement is intended to at least partially mitigate or avoid the disadvantages of the prior art.This object is achieved by a connecting arrangement having the features of claim 1. Preferred features are the subject of the dependent claims. Further advantages and features can be gathered from the general description and from the exemplary embodiments.The connection arrangement according to the invention contains an in particular rigid pipe which contains a thermoplastic and / or a thermosetting plastic, preferably contains at least 50% by volume of a thermoplastic and / or a thermosetting plastic, and a connecting piece for producing a fluid-conducting connection of the pipe to a further component, wherein the connecting piece contains a metal, in particular aluminum, preferably at least 50% by volume. An end section of the tube is pushed onto a connecting piece of the connecting piece and is sealingly pressed onto the connecting piece by means of a retaining ring. The retaining ring contains, preferably to the extent of at least 50% by volume, a metal.The invention is based on the idea of pushing the plastic tube onto a connecting piece of the metallic connecting piece and pressing it onto the connecting piece by means of a metallic retaining ring on the connecting piece. In this way, the plastic tube is clamped between the two metallic components, which leads to a long-lived fluid-tight connection. Preferably, the end section and the connecting piece are designed in such a way that when the end section is pushed onto the connecting piece, a press fit is produced between the end section and the connecting piece. Due to the press fit, the tube expands somewhat and already holds itself on the connecting piece by inherent tension.In a preferred embodiment of the connection arrangement according to the invention, the retaining ring is crimped onto the end section in the radial direction, whereby a permanent pressing of the end section of the pipe can be produced on the connecting piece in a process-safe manner. Alternatively or additionally, the retaining ring can be pushed onto the end section in the axial direction. This has the result, in particular in the case of a press fit present between the end section and the connecting piece, that the correspondingly dimensioned retaining ring can be pressed onto the widened part of the end section and thus a sealing press fit can likewise be produced between the retaining ring and the end section.In a further preferred embodiment of the connection arrangement according to the invention, the connecting piece has conical outer surfaces, cylindrical outer surfaces, convex outer surfaces and / or concave outer surfaces in order to improve the connection. The connecting piece can have, for example, at least in sections, a pine tree profile, a cylindrically stepped profile or a corrugated profile.In a further preferred embodiment of the connection arrangement according to the invention, the connecting piece has one or more circumferential bulges on its outer side in order to improve the connection. In this way, the connecting piece forms structures along its circumference which, when the tube is pressed on, penetrate into the inside of the tube and can thus reinforce the connection. The beads can have, for example, a purely round, semicircular and / or triangular outer cross-sectional contour.In a further preferred embodiment of the connection arrangement according to the invention, the connecting piece forms a flange with at least one through bore. In this way, the connecting piece can be securely fastened or screwed to a further component.In a further preferred embodiment of the connection arrangement according to the invention, for further improving the connection, an inner surface of the end section of the pipe and an outer surface of the connector are bonded to one another with an adhesive and / or are sealed with respect to one another with a sealing compound at least in a part of an axial overlap region. The sealing compound can be, for example, a vulcanized elastomer, in particular an O-ring seal.The connecting piece does not have to be manufactured in one piece with the remaining connecting piece. Instead, it can also be soldered or welded to the remaining connecting piece. In some embodiments, a separately manufactured connection piece can also be connected to the pipe first via the retaining ring and only then fastened to the remaining connecting piece, for example by means of laser welding. Laser welding or other suitable material-bonding joining methods can be used in such a way that a heat generation associated therewith does not have any negative effects on the pipe.It is expressly pointed out that the embodiments of the invention explained above can each be combined with one another individually or in any technically meaningful combination, in each case with the subject matter of claim 1.Modifications and embodiments of the invention and further advantages and details of the invention can be gathered from the following description and the drawings. The schematic figures show: FIG. 1 shows a first embodiment of a connecting device according to the invention in a sectional view; FIG. 2 shows a second embodiment of a connecting device according to the invention in a sectional view with focus on the connecting piece;Identically or similarly acting parts are provided with identical reference numerals, provided that they are used.Individual technical features of the exemplary embodiments described below can also be combined in combination with exemplary embodiments described above and the features of the independent claims and any further claims to form articles according to the invention.FIGS. 1 and 2 show two embodiments of a connection arrangement 10 according to the invention, comprising a pipe 20 and a connecting piece 30 for establishing a fluid-conducting connection of the pipe 20 to a further component. The connecting arrangement 10 defines, at least in the region of the connecting piece 31, a longitudinal central axis L which defines an axial direction running parallel thereto and a radial direction R running orthogonally thereto. A fluid channel 11 extends along the longitudinal central axis L. The connection 32 of the connecting piece is designed to produce a fluid-tight connection with an in particular complementarily shaped counterpart of a further component, such as a further tube, a tank, a heat exchanger or another fluid-conducting device.An end section 21 of the tube 20 is pushed onto a connecting piece 31 of the connecting piece 30 and is sealingly pressed onto the connecting piece 31 by means of a retaining ring 40. In the embodiments shown, the tube 20 is made of a thermoplastic or thermosetting plastic, while the connector 30 and the retaining ring are each formed of a metal.End section 21 and connecting piece 31 are designed in such a way that an interference fit is produced between end section 21 and connecting piece 31. The pipe 20 expands somewhat by the press fit (not shown) and already holds it on the connecting piece 31 by inherent tension. the retaining ring 31 can then be pushed, more precisely pressed, onto the expanded part of the end section 21 from the side facing away from the connecting piece 30, whereby a sealing press fit is likewise produced between the retaining ring 40 and the end section 21. As can be seen, the retaining ring 40 should be arranged within an axial overlap region B of the connecting piece 31 and of the end section 21. Alternatively or additionally, the retaining ring 40 is crimped onto the end section 21 in the radial direction R, whereby a permanent connection between the tube 20 and the connecting piece 30 can be produced in a process-safe manner.The connecting piece 31 is shown in simplified form in the figures and can have conical outer surfaces, cylindrical outer surfaces, convex outer surfaces and / or concave outer surfaces in order to improve the connection. The connecting piece 31 can have, for example, at least in sections, a pine tree profile, a cylindrically stepped profile or a corrugated profile.For improved attachment to another component, the connector 30 forms a flange 50 with a through bore 51.FIG. 2 shows a second embodiment of the connection arrangement 10 according to the invention, which differs from the first embodiment only in the design of the connecting piece 31. the connecting piece 31 has a plurality of encircling beads 312 a, 312 bin this case on its outer side 311, wherein a first bead 312 ahas a round cross-sectional outer contour, while two further beads 312 bhave a triangular cross-sectional outer contour. In this way, the connecting piece 31 forms structures along its circumference which, when the tube 20 is pressed on, penetrate into the inside of the tube 20 and can thus reinforce the connection.In both exemplary embodiments, in order to further improve the tightness, the inner surface 210 of the end section 21 and an outer surface 313 of the connector 31 can be glued to one another with an adhesive and / or sealed with a sealant (not shown) at least in a part of the axial overlap region B.In addition, it should be noted that "having" does not exclude other elements or steps and "a" or "an" does not exclude a plurality.The scope of the present invention is given by the claims and is not limited by the features explained in the description or shown in the figures.

Claims

Connection arrangement (10) comprising a pipe (20) comprising a thermoplastic and / or a thermosetting plastic and a connection piece (30) for producing a fluid-conducting connection of the pipe (10) to a further component, wherein the connection piece (30) comprises a metal, wherein an end section (21) of the pipe (20) is pushed onto a connection piece (31) of the connection piece (30) and is sealingly pressed onto the connection piece (31) by means of a retaining ring (40), wherein the retaining ring (40) comprises a metal.The connector assembly (10) of claim 1, wherein the connector (30) includes aluminum.Connection arrangement (10) according to claim 1 or 2, wherein the end section (21) and the connecting piece (31) are formed in such a way that when the end section (21) is pushed onto the connecting piece (31), a press fit is produced between the end section (21) and the connecting piece (31).Connection arrangement (10) according to one of the preceding claims, wherein the retaining ring (40) is crimped onto the end section (21) in the radial direction (R) and / or is pushed onto the end section (21) in the axial direction (A).Connection arrangement (10) according to one of the preceding claims, wherein the socket (31) has conical outer surfaces, cylindrical outer surfaces, convex outer surfaces and / or concave outer surfaces.Connection arrangement (10) according to one of the preceding claims, wherein the connecting piece (31) has on its outer side (311) one or more circumferential bulges (312a, 312b).Connection arrangement (10) according to one of the preceding claims, wherein the connection piece (30) forms a flange (50) with at least one through-bore (51).Connection arrangement (10) according to one of the preceding claims, wherein an inner surface (210) of the end section (21) of the pipe (20) and an outer surface (313) of the connection piece (31) are bonded to one another with an adhesive and / or are sealed with respect to one another with a sealing compound at least in a part of an axial overlap region (B).

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