DE102014114470A1 - Method for integrating a metallic flexible conduit element in a fluid conduit and flexible conduit element - Google Patents

Abstract

The present invention relates to a method for connecting a metallic flexible conduit element to a further conduit element of a fluid conduit or a connection part, wherein a ring-corrugated bellows 1 is attached directly to the continuing conduit element 5 or the connection part by means of a solder connection directly or indirectly by means of an intermediate sleeve 4 , For this purpose, a bellows 1 is used with a terminal arranged terminal board 2. In the bellows 1, a flexible inner tube 3 is used, which is first fixed axially on the terminal board 2 and / or on the intermediate sleeve 4 and then in the manufacture of the solder joint between the bellows 1 and the continuing line element 5 and the connecting part on the terminal board 2 and / or is attached to the intermediate sleeve 4 and / or on the continuing line element 5 and the connection part by means of soldering.
The invention also relates to a flexible conduit element produced by this process.

Description

The invention relates to a method for integrating a metallic flexible conduit element in a fluid conduit and a flexible conduit member made of metal, namely a method for connecting a metallic flexible conduit member with a further conduit element of a fluid conduit according to the preamble of claim 1, a method for connecting a metallic flexible conduit element with a connection part for connection to a further conducting element of a fluid line according to the preamble of claim 2 and a flexible conduit element made of metal according to the preamble of claim 9.

In a method of the present type, a ring corrugated bellows is fastened by means of a solder joint to a further conducting element or to a connecting part for connection to a further conducting element. This can be done directly, or indirectly by means of an intermediate sleeve.

A flexible conduit element of the present type accordingly comprises a ring-corrugated bellows and at least one continuative conduit element of a fluid conduit or at least one attachment member for connection to a further conducting conduit element of a fluid conduit. The bellows is in this case attached by means of a solder joint on the continuing line element or on the connecting part, in turn, either directly or indirectly by means of an intermediate sleeve. The continuing line element is usually a smooth tube, which can be designed as a bending tube depending on the application.

The incorporation of a metallic flexible conduit member whose main component is a ring corrugated bellows, in a fluid line is not entirely unproblematic because of the mobility of the flexible conduit member, but in particular because of its small wall thickness, which is due to the required mobility. From a cost perspective, solder joints are preferred which ensure a long-term stable and fluid-tight and diffusion-tight connection of the components in simple process steps, for example in a soldering oven.

Examples of methods and flexible conduit members of the present type can be found in the prior art in the DE 25 02 423 A1 and the DE 10 2011 107 886 A1 , While in the former publication a corrugated hose with braiding by means of soldering and with the aid of an outer sleeve is connected with a pipe socket as a continuing line element, the latter publication is concerned with the setting of a connection part for connection to a continuing line element to a metallic corrugated hose by means of a solder joint. Both known techniques have been tested and lead to good results.

Metallic flexible conduit members of the present type are sometimes used to pass hot gases. One field of application in which the present invention is preferably used are exhaust gas recirculation lines in internal combustion engines of motor vehicles. In particular, a high-pressure return line for use in diesel engines, which are charged by a turbocharger and in which the recirculating exhaust gas is removed in the immediate vicinity of the exhaust gas turbine of the turbocharger, must be designed for the passage of gases whose temperature can be above 800 ° C.

Especially for use in exhaust gas recirculation lines of internal combustion engines, in which provide large temperature differences for significant thermal expansion movements, the metal bellows of a flexible conduit member of the present type must be particularly mobile to compensate in particular the thermal expansion movements can. However, this is accompanied by a necessarily small wall thickness of the bellows, with which conventional materials are barely able to withstand the said high temperatures of the fluid passed through.

To solve this problem, therefore bellows are used with materials for the stated application, which are more stable in temperature, but also higher quality and therefore cause higher costs. In addition, materials that withstand such high temperatures for a given low wall thickness are not solderable. In order to incorporate metal bellows made of such materials in a fluid line, therefore, other connection techniques, in particular welding must be used. This also increases the costs.

For other applications in which metal bellows have no solder joints and must be protected from hot gases passed through, such as. In exhaust systems of internal combustion engines, flexible inner tubes are used as liners that sit inside the bellows, guide the gas flow and thermally shield the bellows. The disadvantage of using a flexible inner tube as a liner, however, is that it is particularly axially movable and therefore can not be fixed satisfactorily in the flexible conduit part with a solder joint, especially not in a brazing furnace.

The present invention is therefore based on the object, a method and a flexible To improve line element of the type mentioned above to integrate the flexible conduit member by means of soldering in the fluid line, the ring-corrugated bellows takes no damage even when passing hot gases, even if no special materials are used.

This object is achieved by a method having the features of claim 1 and alternatively by a method having the features of claim 2. Furthermore, this object is achieved by a flexible conduit element with the features of claim 9. Preferred developments of the inventive method can be found in the Claims 3 to 8, advantageous embodiments of the flexible conduit element according to the invention are set forth in claims 10 to 12.

According to a first variant of the method according to the present invention, a ring-corrugated bellows is used with a terminal arranged terminal board for connection to a further conducting element of a fluid line. In the bellows, a flexible inner tube is used, which is initially fixed axially on the connection board or, if present, alternatively or additionally on the intermediate sleeve. When producing the direct or indirect solder joint between the ring corrugated bellows and the continuing line element of the fluid line then the flexible inner tube on the terminal board and / or on the continuing line element and, if present, alternatively or additionally attached to the intermediate sleeve by means of soldering.

A second variant of the method according to the invention provides to use a ring-corrugated bellows with a terminal arranged terminal board and to insert into the bellows a flexible inner tube, which is first fixed axially on the connection board and / or on an optionally existing intermediate sleeve. In accordance with this second variant provided for producing a direct or indirect solder joint between the bellows and a connection part for connection to a continuing line element of a fluid line then the flexible inner tube is attached to the terminal board and / or on the intermediate sleeve and / or on the connecting part by means of soldering.

The metal flexible conduit element according to the invention comprises a ring-corrugated bellows and at least one further conducting element of a fluid line or at least one connection part for connection to a further conducting element of a fluid line. The bellows has at least one end terminal arranged terminal board and is fixed with this directly by means of a solder connection, or indirectly by means of an intermediate sleeve, on the continuing line element or on the connecting part, by means of a solder joint. In the bellows a flexible inner tube is used, which is fastened by means of a solder joint on the terminal board and / or on the intermediate sleeve and / or on the connecting part or on the continuing line element.

The terminal board of the ring-corrugated bellows used according to the invention can be cylindrical or, if no bellows with a circular cross-section is used, be formed corresponding flattened, or also have a conical shape. It may have a cross section which substantially corresponds to the inner cross section of the bellows or else has a cross section which is larger and corresponds, for example, to the outer cross section of the bellows.

Particularly preferably, the solder joints according to the invention are produced together in a soldering oven, preferably in a continuous soldering oven.

The previously provided according to the invention axial fixing of the flexible inner tube on the terminal board and / or on the intermediate sleeve can be made by welding, in particular by spot welding. Spot welding ensures reliable axial fixation without damaging the bellows or its connection board. A metallic ring-corrugated bellows and its terminal board are formed in the preferred field of the present invention is usually very thin-walled, so that often there is not enough material to reliably exclude that arise during welding holes in the material. If only spot-welded, such holes do not disturb, especially since they are closed or covered in the subsequent soldering, usually by the liquefied solder material.

To avoid a welding process, or to achieve additional stability, the flexible inner tube can also be fixed by pressing or crimping on the terminal board and / or on the intermediate sleeve. It is advantageous if a bellows is used with a conically extending terminal board, so that an axial fixation can be achieved for example by radially pressing an end portion of the flexible inner tube with the conical terminal board.

As a flexible inner tube, all kinds of metallic flexible conduit elements can be used, in particular metal hoses, which are composed of individual segments or made of one or more metal profiles. Winding tubes made of metal profiles are preferred in the context of the present invention for use as a flexible inner tube; especially Agraffschläuche are advantageous to use, since these are both flexible and relatively dense and so shield the bellows particularly well against, for example, hot gases.

The connecting part used according to a variant of the present invention, which is to be fixed directly or indirectly to the ring-corrugated bellows by means of soldering, may be a flange or a connecting part with internal or external thread; Preferably, it can also be a V-board, which offers the additional advantage that it can be used as an intermediate sleeve to which in particular the flexible inner tube can be fixed.

A preferred embodiment of the method according to the invention consists of the following method steps: First, the flexible inner tube and the terminal board of the bellows are radially compressed with an externally placed on the port board and axially over this protruding intermediate sleeve. Thereafter, the flexible inner tube, the terminal board and the intermediate sleeve are fixed by welding together. Then, the continuing line element or the connecting part is attached axially to an end face of the flexible inner tube by being inserted into the intermediate sleeve, after which the terminal board of the bellows, the further lead element or the connecting part, the intermediate sleeve and the flexible inner tube are soldered together, optionally after previously applying a solder paste. The soldering process can preferably be carried out in a continuous soldering oven.

In the context of the present invention, it is preferable to connect the corresponding components by brazing. Unexpectedly, it has been found that the necessary high temperatures, especially in a brazing furnace, adversely affect neither the flexibility and function of the ring-corrugated bellows nor those of the flexible inner tube.

The use of an intermediate sleeve in the context of the present invention makes it possible, in particular, to avoid cracks in the inside diameter between the flexible inner tube and a further conducting element. This improves the flow guidance in the fluid line.

Several exemplary embodiments of flexible conduit elements designed according to the invention, on the basis of which concrete exemplary embodiments of a method according to the invention are illustrated, are described and explained in more detail below with reference to the attached drawings. Show it:

1a to 1d the production of a flexible conduit element designed according to the invention in four method steps according to the invention, in schematic lateral sectional views;

2a a schematic sectional side view of another embodiment of an inventively designed flexible conduit element;

2 B a schematic sectional side view of a variant of the embodiment of 2a .

3 a schematic sectional side view of another embodiment of an inventively designed flexible conduit element;

4a FIG. 2 a schematic side sectional view of a further exemplary embodiment of a flexible conduit element designed according to the invention, FIG.

4b a variant of the embodiment 4a ;

5a FIG. 2 a schematic side sectional view of a further exemplary embodiment of a flexible conduit element designed according to the invention, FIG.

5b a variant of the embodiment 5a ;

That in the 1a to 1d made in four illustrated process steps flexible conduit element consists essentially of a ring corrugated bellows 1 with two terminally arranged connection shelves 2 . 2 ' , designed as a winding tube flexible inner tube 3 , an intermediate sleeve 4 and a continuing line element 5 ,

In the in 1a The method step shown becomes an end region 6 the flexible inner tube 3 , the connection board 2 and the intermediate sleeve 4 by means of a pressing tool 7 in the direction of the arrow 8th radially pressed together by the end portion 6 the flexible inner tube 3 and the intermediate sleeve 4 be easily widened.

To the flexible inner tube 3 additionally axially on the connection board 2 and the intermediate sleeve 4 To fix, these components, as in 1b represented by means of a symbolically illustrated welding device 9 welded spot welded together by spot welding. Spot welding with the welding machine 9 thus captures the intermediate sleeve 4 , the end area 6 the flexible inner tube 3 as well as between these two components sandwiched outlet board 2 of the ring-corrugated bellows 1 ,

The thus fixed components of the flexible conduit member, as 1c shows, with a continuing line element 5 axially joined, with a holding tool 10 attached to the intermediate sleeve 4 engages, the counterforce generated when inserting the continuing line element 5 in the intermediate sleeve 4 or in an axial compression in the direction of the arrow 11 necessary is.

As 1d shows, is the continuing line element 5 after the axial pressing blunt end face at the end 6 the flexible inner tube 3 set, with the intermediate sleeve 4 the corresponding place completely covered. After applying a solder paste 12 will the in 1d represented, fixed by compression and spot welding assembly in a continuous soldering furnace, where it is brazed.

As far as the illustrated flexible conduit element is intended for use in an exhaust gas recirculation line, the typical wall thickness of the bellows is 1 often not more than 0.2 mm, which is why it is beneficial in 1b Spot welding performed so that the terminal board 2 of the bellows 1 between the intermediate sleeve 4 and the end area 6 the flexible inner tube 3 lies. The flexible inner tube 3 is in the present embodiment preferably a winding tube of Agraffprofilen so that he the bellows 1 effectively protects against hot gases passing through.

In the 2a and 2 B show two variants of a further embodiment of an inventively designed flexible conduit element, again in a schematic side sectional view. In both variants comes an intermediate sleeve 4 with a diameter jump for use, which allows the flexible inner tube 3 with a radial distance to the bellows 1 and its connection shelves 2 . 2 ' is held. This improves the thermal shielding of the bellows 1 of about passed hot gases in addition. Further, in this way a fretting between the bellows 1 and the flexible inner tube 3 excluded, and a further advantage of this embodiment is that the flexible inner tube 3 a greater length than the bellows 1 may significantly increase the mobility of the flexible conduit element overall.

The method step according to the invention, in which the flexible inner tube 3 on the connection board 2 is axially fixed here is logically only indirectly via the intermediate sleeve 4 in that, on the one hand, in a connection region between the intermediate sleeve 4 and the connection board 2 welds 13 set and on the other hand in a connection region between the intermediate sleeve 4 and the end area 6 the flexible inner tube 3 welds 13 ' be set. A direct connection between the flexible inner tube 3 and the bellows 1 or its connection board 2 not done.

The continuing leadership 5 is then on the intermediate sleeve 4 plugged like this 2a and 2 B demonstrate. In 2 B Here, a variant is shown, in which the continuing line element 5 with a widening 14 is provided, so that in the interior of the flexible conduit element results in a total of no diameter jump, as in 2a the case is.

In the in the 2a and 2 B represented by means of welding points 13 . 13 ' and by press fit of the continuing conduit element 5 on the intermediate sleeve 4 fixed state, the assembly is provided with (not shown here) solder paste and then brazed in a brazing furnace. If due to a particularly thin bellows 1 when setting the welding points 13 in the connection area between the intermediate sleeve 4 and the connection board 2 of the bellows 1 Holes in the connection board 2 In any case, this is not disturbing because they are covered by the solder material during soldering.

3 shows a variant of the in the 2a and 2 B illustrated embodiments, in turn, an intermediate sleeve 4 is used with a diameter jump to attach a (not shown here) continuing line element can. However, here is the flexible inner tube 3 not directly on the intermediate sleeve 4 fixed, but directly on the connection board 2 of the bellows 1 , The intermediate sleeve 4 and the end area 6 the flexible inner tube 3 sandwich the attachment board between them, leaving the weld spot 13 the intermediate sleeve 4 , the connection board 2 and the flexible inner tube 3 axially fixed to each other.

4a shows, again in a schematic lateral sectional view, a further embodiment of an inventively designed flexible conduit element. Here is the connection board 2 directly with a flange 15 connected, with the end portion 6 of the inner tube 3 according to the invention with the terminal board 2 and the flange 15 with soldered. For axially fixing the end region 6 the flexible inner tube 3 serves a welding point 13 , which is the flexible inner tube 3 , the connection board 2 and the flange 15 determines each other. This will close the flange 15 and the end area 6 the flexible inner tube 3 the connection board 2 of the bellows 1 sandwiched between them, so that in so far the flange 15 the task the intermediate sleeve 4 of the embodiment according to 3 takes over.

As 4b shows, in a variant of the flange 15 also indirectly, via an intermediate sleeve 4 , with the connection board 2 and the end area 6 the flexible inner tube 3 get connected. The welds 13 for the axial fixing of the flexible inner tube according to the invention 3 on the connection board 2 is here in the overlap area between the intermediate sleeve 4 , the connection board 2 and the end area 6 the flexible inner tube 3 set.

The in the 5a and 5b illustrated embodiments correspond to those in the 4a and 4b illustrated embodiments, the only difference being that instead of a flange 15 a V-board 16 is used as a connection part for connection to a further conducting element. Accordingly, on the further description of the 4a and 4b Be referred.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2502423 A1 [0005]
• DE 102011107886 A1 [0005]

Claims (12)

Method for connecting a metallic flexible line element to a further line element of a fluid line, wherein a ring-corrugated bellows ( 1 ) by means of a solder joint directly, or by means of an intermediate sleeve ( 4 ) indirectly, at the continuing line element ( 5 ), characterized in that a bellows ( 1 ) with a terminal arranged terminal board ( 2 ) for direct or indirect connection to the continuing line element ( 5 ) is used, and that in the bellows ( 1 ) a flexible inner tube ( 3 ), which is initially at the terminal board ( 2 ) and / or on the intermediate sleeve ( 4 ) axially fixed and then during manufacture of the solder joint between the bellows ( 1 ) and the continuing line element ( 5 ) on the connection board ( 2 ) and / or on the intermediate sleeve ( 4 ) and / or on the continuing line element ( 5 ) is fixed by means of soldering. Method for connecting a metallic flexible line element to a connection part for connection to a further line element of a fluid line, wherein a ring-corrugated bellows ( 1 ) by means of a solder joint directly, or by means of an intermediate sleeve ( 4 ) indirectly, is fastened to the connecting part, characterized in that a bellows ( 1 ) with a terminal arranged terminal board ( 2 ) is used, and that in the bellows ( 1 ) a flexible inner tube ( 3 ), which is initially at the terminal board ( 2 ) and / or on the intermediate sleeve ( 4 ) axially fixed and then during manufacture of the solder joint between the bellows ( 1 ) and the connection part on the connection board ( 2 ) and / or on the intermediate sleeve ( 4 ) and / or attached to the connection part by means of soldering. Method according to one of claims 1 or 2, characterized in that the flexible inner tube ( 3 ) by welding, in particular by spot welding on the terminal board ( 2 ) and / or on the intermediate sleeve ( 4 ) is fixed. Method according to one of claims 1 to 3, characterized in that the flexible inner tube ( 3 ) by pressing or crimping on the terminal board ( 2 ) and / or on the intermediate sleeve ( 4 ) is fixed. Method according to claim 4, characterized in that a bellows ( 1 ) is used with a conical terminal board. Method according to at least one of claims 1 to 5, characterized in that the flexible inner tube ( 3 ) and the connection board ( 2 ) of the bellows ( 1 ) with an outside on the terminal board ( 2 ) and axially over this projecting intermediate sleeve ( 4 ) are pressed radially, then the flexible inner tube ( 3 ), the connection board ( 2 ) and the intermediate sleeve ( 4 ) are fixed to one another by welding, then the further conducting element ( 5 ) or the connecting part axially to an end face of the flexible inner tube ( 3 ) is applied by placing it in the intermediate sleeve ( 4 ), after which the terminal board ( 2 ) of the bellows ( 1 ), the continuing line element ( 5 ) or the connecting part, the intermediate sleeve ( 4 ) and the flexible inner tube ( 3 ) are soldered together. Method according to at least one of claims 1 to 6, characterized in that the production of the solder joint and the fixing of the flexible inner tube ( 3 ) in a soldering oven. Method according to at least one of claims 1 to 7, characterized in that as a flexible inner tube ( 3 ) a winding tube made of one or more metal profiles is used. Metal flexible pipe element, in particular produced by a process according to at least one of claims 1 to 8, comprising a ring-corrugated bellows ( 1 ) and at least one further conducting element ( 5 ) a fluid line or at least one connection part for connection to a further line element of a fluid line, wherein the bellows ( 1 ) by means of a solder joint directly, or by means of an intermediate sleeve ( 4 ) indirectly, at the continuing line element ( 5 ) or fastened to the connecting part, characterized in that the bellows ( 1 ) at least one terminally arranged terminal board ( 2 ), to which the further conducting element ( 5 ) or the connection part is fixed directly or indirectly by means of a solder connection, and that in the bellows ( 1 ) a flexible inner tube ( 3 ), which by means of soldering on the terminal board ( 2 ) and / or on the intermediate sleeve ( 4 ) and / or at the connecting part or continuing line element ( 5 ) is attached. Flexible conduit element according to claim 9, characterized in that the flexible inner tube ( 3 ) is a winding tube made of one or more metal profiles. Flexible conduit element according to one of claims 9 or 10, characterized in that the connection part is a flange ( 15 ) or a V-board ( 16 ). Flexible conduit element according to at least one of claims 9 to 11, characterized in that the connection board ( 2 ) of the bellows ( 1 ) and the flexible inner tube ( 3 ) on the one hand, and the continuing line element ( 5 ) or the connecting part on the other hand end face blunt are juxtaposed and thereby form a joint, wherein the joint of an intermediate sleeve ( 4 ) which is connected to the connection board ( 2 ), the continuing line element ( 5 ) or connecting part as well as with the flexible inner tube ( 3 ) is soldered.

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