DE102018118801A1 - Pipe element with inner tube made of profiled tape - Google Patents

Abstract

The invention relates to a line element (100) for exhaust gases, which has a gas-tight outer hose (AS) and an inner hose (IS) arranged therein. The inner tube (IS) is designed as a winding tube, the adjacent profile strip turns of which are connected to one another without gaps. This makes the inner hose liquid-tight and can prevent the penetration of additives such as catalysts for exhaust gas aftertreatment into the space between the inner hose (IS) and the outer hose (AS).

Description

The invention relates to a line element for exhaust gases, which can be used, for example, as a so-called decoupling element in motor vehicles for decoupling vibrations between the engine and subsequent parts of the exhaust system.

From the DE 20 2015 104 177 U1 Various embodiments of line elements are known which consist of an inner hose and an outer hose, with at least one of the hoses generally being gas-tight. Further state of the art can be found in the DE 10 2015 102 258 A1 (Touching inner tube and outer tube), WO 2017/016728 A1 (Line element with friction contact protection) and WO 2018/077613 A1 (Pipe element made of several coaxial hoses). All of the documents mentioned are fully incorporated into the present application by reference.

In modern diesel engines, a catalytic converter for exhaust gas aftertreatment is usually added to the exhaust gas, in particular for the reduction of nitrogen oxides (AdBlue ^® ). It turns out that such additives can impair the function of the line elements described above.

Against this background, it is an object of the present invention to provide line elements with improved operating properties, in particular when directing exhaust gas flows mixed with additives.

This object is achieved by a line element with the features of claim 1. Advantageous refinements are contained in the subclaims.

The line element according to the invention for use in an exhaust system essentially contains two components, namely a gas-tight outer hose and an inner hose which is arranged coaxially in the outer hose. The inner tube is a wrapping tube which has been produced from (at least) one profiled band (“profiled band”) by winding, whereby adjacent profiled band windings in the finished wrapping tube are connected to one another without gaps. The “gap-free” connection or contact between adjacent profile strip windings is to be understood in a macroscopic sense in such a way that the maximum distance (air gap) between the adjacent profile strip windings should be less than 0.1 mm, preferably less than 0.05 mm, particularly preferably less than 0.01 mm. Such freedom from gaps has the consequence that the inner tube can be regarded as liquid-tight for practical purposes, since any leakage of liquid that may still occur from the inner tube remains in a negligible order of magnitude.

Absolute tightness, especially gas tightness, should not be excluded; however, it is not absolutely necessary for the inner tube. Furthermore, the described freedom from gaps in the connection or contact of adjacent profile strip windings is typically present along the entire helical contact area between adjacent profile strip windings, so that there is no gap connection to the outer region at any point on the inner tube.

The liquid density of the inner hose means that (essentially) no liquid additives such as, for example, an added catalyst for reducing nitrogen oxides from the exhaust gas flow get into the space between the inner hose and the outer hose. This avoids functional impairments that could result from sooting and / or crystallization of these additives. In this way, a robust, durable line element is provided.

There are various options for the design of the inner tube.

In particular, the edge sections of adjacent profile strip windings can be hooked to one another, suitable edge geometries, for example, the DE 20 2015 104 177 U1 can be removed.

Additionally or alternatively, the edge sections of adjacent profile strip windings can be integrally connected to one another, for example by welding or soldering (cf. DE 10 2010 037 772 A1 ).

Furthermore, additionally or alternatively, the edge sections of adjacent profile strip windings can be pressed together, caulked, knurled or toxed.

Due to the above-mentioned configurations of the edge sections, they come into close and thus gap-free contact. The configurations can preferably also be combined with one another. In particular, initially not gap-free, movable hooking of edge sections, such as that from the DE 20 2015 104 177 U1 are known to be converted by pressing into a gap-free form as defined above.

The gap-free connection or contact of adjacent profile strip windings generally means that the winding tube is axially stretchable (and compressible), which guarantees the desired flexibility with conventional line elements. In order to compensate for this effect, the profile strip from which the winding tube is made can have elastic compression sections. These sections, which typically extend parallel to the axis of the tube in the finished winding tube, are elastic in an axial, radial and / or torsional manner. Compression sections of this type are preferably designed as constrictions or bulges which are wavy in axial section. The compression sections result in flexibility of the winding tube on the basis of the elastic material behavior, even if adjacent profile strip windings are fixed to one another.

Additionally or alternatively, in order to increase the flexibility of the line element, the inner tube can be fixed at one axial end relative to the outer tube and at the other axial end opposite it can be mounted so as to be axially displaceable relative to the outer tube. Any greater stiffness of the inner tube compared to the outer tube can be compensated in this way, since one end of the inner tube can move axially freely relative to the outer tube. Preferably, the downstream end of the inner tube with respect to the exhaust gas is mounted such that it can be moved.

In addition to the one-sided displacement movement on the other side, a further embodiment of the mounting of the inner element provides a bearing with degrees of freedom in one to three spatial directions, preferably in four spatial directions, instead of a fixed bearing.

The inner tube and the outer tube are preferably in contact with one another at points, in a line, in partial area or over the entire area. As a result, vibration damping is constructively achieved without any additional measures or components (such as a damping material).

According to a further embodiment, a friction-reducing material is provided in the contact area between the inner tube and the outer tube. The friction-reducing material can be formed, for example, as a coating or in the form of a suitable choice of material for the outer layer of a multi-layer hose material. Of two layers of a hose or profile strip, one can in particular act as a carrier layer and the second layer can form the friction-reducing layer (wear carrier layer). The friction-reducing material is preferably softer than the material of the friction partner. Suitable anti-friction materials include stainless steel, steel, zinc, zinc phosphate, aluminum, aluminum alloys, copper, titanium, tantalum, ceramic, nickel, nickel-based alloys, graphite, aramids, brass, bronze and / or molybdenum sulfide. Further details on such an embodiment can be found in the WO 2017/016728 A1 ,

Additionally or alternatively, the abovementioned friction-reducing material can be provided in an intermediate body arranged between the inner tube and the outer tube. This can be, for example, a (wire) knitted fabric that surrounds the inner tube. Furthermore, a wire, a tube, a band or the like made of the friction-reducing material can be wrapped around the inner tube, this preferably engaging positively in corrugations of the inner tube and / or outer tube. Furthermore, a further hose (e.g. a winding hose) made of the friction-reducing material can be arranged between the inner hose and the outer hose.

According to a further embodiment, a friction-reducing layer is provided in the contact area between the inner tube and the outer tube. The friction-reducing layer can be formed, for example, as a coating or in the form of a suitable choice of material for the outer layer of a multi-layer hose material. Of two layers of a hose or profile strip, one can in particular act as a carrier layer and the second layer can form the friction-reducing layer (wear carrier layer). The friction-reducing layer is preferably softer than the material of the friction partner. Suitable materials for the anti-friction layer include stainless steel, steel, zinc, zinc phosphate, aluminum, aluminum alloys, copper, titanium, tantalum, ceramic, nickel, nickel-based alloys, graphite, aramids, brass, bronze and / or molybdenum sulfide. Further details on such an embodiment can be found in the WO 2017/016728 A1 ,

• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch einen weiteren aus z.B. Kupfer gefertigten, einlagigen Wickelschlauch gebildet wird.
• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch ein aus z.B. Kupferdraht hergestelltes gestricktes Drahtgestricke / Drahtgestrickestrumpf gebildet wird.
• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch ein im Prozess parallel oder nachträglich umwickeltes z.B. aus Kupfer bestehendes Metallband wiedergegeben wird.
• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch eine Funktionsbeschichtung (Gleitlack, Molybdänsulfid, Molybdändisulfid, Bornitrit, PVD- oder CVD-Beschichtungssysteme) gebildet wird.
• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch z.B. aus Kupfer gefertigtem Draht ist, welcher in den Tälern des einlagigen Profils mit Verbindungsabschnitt und Kompressionsabschnitt zum Liegen kommt. Dabei ist der Durchmesser des Drahtes derart gewählt, dass die Drahtoberflächen über die Außenkanten des Innenschlauch radial hinausragen.
• • Innenschlauch nicht aus 2 Bandlagen hergestellt, sondern bestehend aus einem einlagigen Profil mit Verbindungsabschnitt und Kompressionsabschnitt, bei der die Reibschicht durch z.B. aus Kupfer gefertigtem Rohr ist, welches in den Tälern des einlagigen Profils mit Verbindungsabschnitt und Kompressionsabschnitt zum Liegen kommt. Dabei ist der Durchmesser des Rohres derart gewählt, dass dessen Oberfläche über die Außenkanten des Innenschlauch radial hinausragt.

Further designs for the arrangement of a friction-reducing material between the inner hose and outer hose are:

• • The inner tube is not made from two layers of tape, but consists of a single-layer profile with a connecting section and compression section, in which the friction layer is formed by a further single-layer winding tube made of, for example, copper.
• • Inner hose not made of 2 layers of tape, but consisting of a single-layer profile with a connecting section and compression section, in which the friction layer is knitted using a piece made of, for example, copper wire Wire mesh / wire mesh stocking is formed.
• • The inner tube is not made from two layers of tape, but consists of a single-layer profile with a connecting section and compression section, in which the friction layer is reproduced by a metal tape, for example made of copper, wrapped in parallel or subsequently in the process.
• • The inner tube is not made of two layers of tape, but consists of a single-layer profile with a connecting section and compression section, in which the friction layer is formed by a functional coating (sliding varnish, molybdenum sulfide, molybdenum disulfide, boron nitride, PVD or CVD coating systems).
• • The inner tube is not made from 2 layers of tape, but consists of a single-layer profile with a connecting section and compression section, in which the friction layer is made of, for example, wire made of copper, which comes to rest in the valleys of the single-layer profile with a connecting section and compression section. The diameter of the wire is chosen such that the wire surfaces protrude radially beyond the outer edges of the inner tube.
• • Inner hose not made of 2 layers of tape, but consisting of a single-layer profile with connecting section and compression section, in which the friction layer is, for example, a tube made of copper, which comes to rest in the valleys of the single-layer profile with connecting section and compression section. The diameter of the tube is chosen such that its surface protrudes radially beyond the outer edges of the inner tube.

The outer hose of the line element can be designed as a corrugated bellows, a winding bellows, or a membrane bellows. Corrugated bellows are typically produced from a tube by internal high pressure forming in connection with an upsetting operation. Winding bellows and membrane bellows are welded, rotationally symmetrical or helically corrugated elements in the profile area, which have either corrugations that are pronounced perpendicular to the axis of rotation or spiral corrugations. A wound bellows structure can preferably be hooked in a form-fitting manner or overlapped or welded in a material-fitting manner. Such elements are used, for example, in the DE 10 2008 001 297 A1 or the DE 10 2011 053 131 A1 described.

Each of the hoses of the line element, in particular the inner tube, can have a non-circular (“non-circular”) cross section, preferably an oval or polygonal cross section, at least in an axial section of the line element. When placing a hose with a non-round cross-section in a hose with a round cross-section (or otherwise non-round cross-section), a damped vibration behavior can be ensured via a line contact. Further details of such embodiments can be found in the DE 10 2015 102 258 A1 , the DE 10 2018 102 101 A1 or the DE 10 2012 013 946 A1 be removed.

• 1 einen Längsschnitt entlang der Erstreckungsachse eines erfindungsgemäßen Leitungselementes;
• 2 eine vergrößerte separate Darstellung des Innenschlauches von 1.

The invention is explained in more detail below with the aid of the attached figures using an exemplary embodiment. It shows:

• 1 a longitudinal section along the extension axis of a line element according to the invention;
• 2 an enlarged separate representation of the inner tube of 1 ,

• - Einem radial außen liegenden gasdichten Außenschlauch „AS“, der im Ausführungsbeispiel die Form eines wendelgewellten Membranbalgs 110 hat.
• - Einem koaxial im Außenschlauch AS angeordneten Innenschlauch „IS“, welcher als Wickelschlauch aus schraubengangförmig umlaufenden Windungen eines Profilbandes 121 ausgebildet ist.

1 shows a section along the longitudinal axis through the wall of a line element 100 according to an embodiment of the present invention. The management element 100 extends between two connection elements 101 , which are provided on the input side of the exhaust gas (left in the figure) or the output side of the exhaust gas (right, not shown) and are provided for connection to the other components of the engine and the exhaust system. The management element 100 consists essentially of two components, namely:

• - A radially outer gas-tight outer tube "AS", which in the exemplary embodiment has the shape of a helically corrugated membrane bellows 110 Has.
• - An inner hose “IS”, which is arranged coaxially in the outer hose AS and which is a winding hose made of spiral turns of a profile strip 121 is trained.

The last-mentioned inner hose IS is in 2 shown enlarged. In the exemplary embodiment, it is designed in two layers, that is to say the profiled strip 121 consists of an inner layer 124 made of a hard carrier material and a friction-reducing and generally softer outer layer 125 , This provides friction protection in the contact area with the outer hose AS. The thickness of the outer layer 125 (eg copper) can be, for example, approximately 0.01 mm to 0.5 mm, that of the inner layer 124 (e.g. stainless steel of grade 1.4828) approx. 0.1 mm up to 0.5 mm.

• - Wickelschlauch aus reibminderndem Material (z.B. Agraffschlauch aus Kupfer) befindet sich zwischen Innenschlauch IS und Außenschlauch AS.
• - Gestricke aus reibminderndem Material (z.B. Kupfer) befindet sich zwischen Innenschlauch IS und Außenschlauch AS.
• - Beschichtung aus reibminderndem Material (z.B. Kupfer) ist als Reibpartner auf Innenschlauch IS und/oder Außenschlauch AS.
• - Reibminderndes Material (z.B. Kupfer) als Draht oder Rohr ist eingewickelt in Wellungen des Innenschlauches IS derart, dass es über die Wellungen hinausragt und damit die Reibebene ausbildet gegenüber dem Außenschlauch AS.
• - Reibminderndes Material (z.B. Kupfer) ist als dünnes Band über die Wellungen des Innenschlauches IS gewickelt (ähnlich einer medizinischen Bandage).

Except for the outside location 125 of the multi-layer inner hose IS shown, a friction-reducing material can also be brought into the contact area between the inner hose IS and the outer hose AS in numerous other ways. For example, the following structures can exist:

• - Wrapping hose made of friction-reducing material (e.g. copper agraff hose) is located between the inner hose IS and outer hose AS.
• - Knitted fabrics made of friction-reducing material (e.g. copper) are located between the inner hose IS and outer hose AS.
• - Coating made of friction-reducing material (eg copper) is a friction partner on the inner hose IS and / or outer hose AS.
• - Friction-reducing material (eg copper) as wire or tube is wrapped in corrugations in the inner hose IS in such a way that it projects beyond the corrugations and thus forms the friction plane with respect to the outer hose AS.
• - Friction-reducing material (eg copper) is wound as a thin band over the corrugations of the inner hose IS (similar to a medical bandage).

Furthermore, the (two-ply) profile tape 121 , from which the inner tube IS is wound, with a central compression section 122 provided which in the longitudinal section of 1 is wavy. Through the compression sections 122 the inner hose IS receives a desired (especially axial) flexibility.

The edges 123 of the profile tape 121 are bent through 180 ° for the purpose of hooking to the edge of an adjacent profile strip turn. In contrast to a conventional winding hose, the interlocking is not carried out with a play which would allow relative axial movement of adjacent profile strip windings. Instead, adjacent profile strip windings are connected to one another without gaps by pressing. Additionally or alternatively, a cohesive connection of adjacent profile strip windings in the overlap area can also take place, for example by welding or soldering.

Due to the gap-free fixing of adjacent profile tape turns to one another, the inner hose IS becomes liquid-tight for practical purposes and can therefore prevent the ingress of liquids such as catalysts (AdBlue®) from the exhaust gas in the inner hose into the space between the inner hose and the outer hose AS. Problems due to stiffening of the system due to the sooting and / or crystal insulation of such substances are thus avoided.

To ensure sufficient axial flexibility of the line element 100 To ensure despite the fixation of adjacent profile tape turns of the inner tube, in the embodiment shown (next to the compression sections 122 ) a one-sided sliding seat is provided. Here is the upstream end 126 of the inner hose IS via the connection element 101 fixedly connected to the outer hose AS, while the downstream end (not shown) is mounted axially displaceably relative to the outer hose via a sliding seat in the connecting element there.

The inner tube IS preferably has a non-circular, for example oval, cross section (perpendicular to the plane of the drawing), while the cross section of the outer tube AS is circular. This results in a line contact between the inner hose IS and outer hose AS, which ensures the desired damping behavior of the entire system.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for better information for 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.

Patent literature cited

• DE 202015104177 U1 [0002, 0010, 0013]
• DE 102015102258 A1 [0002, 0023]
• WO 2017/016728 A1 [0002, 0018, 0020]
• WO 2018/077613 A1 [0002]
• DE 102010037772 A1 [0011]
• DE 102008001297 A1 [0022]
• DE 102011053131 A1 [0022]
• DE 102018102101 A1 [0023]
• DE 102012013946 A1 [0023]

Claims (9)

Pipe element (100) for exhaust gases, comprising a gas-tight outer tube (AS) and an inner tube (IS) arranged therein, the inner tube being a winding tube made of a profile strip (121), the adjacent profile strip turns of which are connected to one another without gaps. Pipe element (100) after Claim 1 , characterized in that the edge sections (123) of adjacent profile strip windings are hooked together and / or are integrally connected to one another and / or are pressed together. Pipe element (100) according to at least one of the preceding claims, characterized in that the profile strip (121) has elastic compression sections (122). Pipe element (100) according to at least one of the preceding claims, characterized in that the inner tube (IS) is fixed relative to the outer tube (AS) at one axial end (126) and is mounted on the other axial end (127) so as to be displaceable. Pipe element (100) according to at least one of the preceding claims, characterized in that the outer hose (AS) and the inner hose (IS) are in point, line, partial or full surface contact. Pipe element (100) according to at least one of the preceding claims, characterized in that a friction-reducing material (125) is provided in the contact area of the inner hose (IS) and outer hose (AS). Line element after Claim 6 , characterized in that the friction-reducing material - is provided in a layer (125) of the inner tube (IS) and / or the outer tube (AS); - In an intermediate body arranged between the inner tube (IS) and the outer tube (AS), such as in particular a knitted fabric, a wire, a tube, a band and / or a further tube. Pipe element (100) according to at least one of the preceding claims, characterized in that the outer hose (AS) is a corrugated bellows, a bellows or a membrane bellows. Pipe element (100) according to at least one of the preceding claims, characterized in that the inner tube (IS) and / or the outer tube (AS) has a non-circular cross-section, preferably an oval or polygonal cross-section, at least in an axial section of the line element.

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