DE202007004757U1 - Decoupling element with insulation - Google Patents

Abstract

decoupling (E) for use with exhaust systems and of substantially hollow cylindrical Shape with particular circular or near oval cross-section and with at least one end (10), which for Connection of a line element (5) to the decoupling element (E) is suitable, and arranged with at least two substantially coaxially Layers (1, 1 ', 2, 3, 4), characterized in that in the area the at least one end (10) of the decoupling element (E) an insulating layer (7) is provided for thermal insulation.

Description

The The invention relates to a decoupling element for use with exhaust systems and of substantially hollow cylindrical shape with particular circular or approximately oval cross-section and at least one end, which for connecting a conduit element is suitable for the decoupling element, and with at least two in Essentially coaxially arranged layers.

such Entkoppelelemente are usually as an intermediate piece interposed in exhaust pipes or systems of motor vehicles, to record movements and vibrations and from forwarding decouple to adjacent components. Usually arise Such movements and vibrations by an elastically mounted Drive machine as a result of load change reaction in normal driving. Such a decoupling element must also thermal length changes compensate for the exhaust pipe caused by the heating of the exhaust pipe caused by hot exhaust gases of the prime mover.

Usually These decoupling consist of at least two coaxial Layers, where as innermost layers a gas-carrying component and a helical or ring corrugated metal bellows are provided. The different layers increase or improve the mobility of the decoupling element, at the same time protect they the decoupling against damage from the outside and ensure its gas tightness. To reduce Of pollutants in the exhaust of the prime mover are often downstream the decoupling element in the exhaust pipe usually catalysts or diesel particulate filter arranged. So this faster operating temperature and thus achieve reduced exhaust emissions, It is necessary that the temperature of the exhaust gas during passage by the decoupling unnecessary by additional Heat radiation is reduced. At the entrance of the exhaust gas in the catalyst this is the catalyst as possible quickly to the optimum effect for reducing exhaust emissions heat required operating temperature. In case of Diesel engines are the highest possible temperatures of the exhaust gas also necessary to the temperature-dependent regeneration diesel particulate filters. Currently common Diesel engines produce relatively low exhaust gas temperatures. This In particular, it has a negative effect on the aforementioned regeneration the diesel particulate filter off when there is an extra Cooling of the exhaust gases when passing through the decoupling element comes. Ultimately, this means a worse regeneration of diesel particulate filters.

This Problem tries to circumvent in the prior art, that relatively expensive surface coatings used for diesel particulate filters be or additive systems. These reduce those for regeneration the particulate filter required minimum exhaust gas temperature.

Furthermore, from the DE 103 93 976 T5 Also known is a flexible tube, which at least partially has an air gap between the radially innermost layer, which is designed as a gas-carrying component, and the radially closest to the outer layer of a corrugated metal bellows. The air gap prevents excessive heat radiation of the flexible tube. Thus, it is possible to reduce the exhaust gas temperature reduction after passage of the gas through the flexible pipe.

task Therefore, it is the heat radiation of the present invention a decoupling easily and inexpensively on minimize without the damping properties of the decoupling element thereby be worsened.

These The object is achieved according to the invention in the region of the at least one end of the decoupling element provided an insulating layer for thermal insulation is.

By using an insulating layer for thermal insulation, a reduced heat radiation is also achieved for the first time in the region of the at least one end of the decoupling element. Opposite the flexible tube from the DE 103 39 976 T5 , in which at the two ends of the air gap for insulation due to the directly successive or juxtaposed different layers is no longer present and thus increased heat radiation in the region of the ends of the flexible tube is the result, is the total by the use of the insulating layer according to the invention Temperature of the exhaust gas during flow passage through the decoupling less reduced. Catalysts or diesel particulate filters arranged downstream of the decoupling element more quickly reach the operating temperature necessary for the reduction of pollutants or the regeneration of the particulate filter. If the insulating layer is arranged on a radial inner side of at least one layer, as is particularly expedient, the insulating layer is shielded from damage from the outside, so that an expensive protective coating of the insulating layer can be dispensed with.

Conveniently, a connected to the decoupling element line element via a cohesive connection, in particular via a welded joint, fixed to at least one position of the decoupling element. This will be a simple and inexpensive way to determine the line element shown on the decoupling element.

In order to the insulating layer in the region of the at least one end of the decoupling element not due to movements and vibrations of the prime mover in their position on at least one end of the decoupling element slipped out of its original position and with it the heat radiation then only partially isolated one Increased end, it is appropriate if a stop for the mobility of the insulating layer in at least one axial direction is arranged.

Especially It is advantageous if the stop by the common cohesive connection is formed. This accounts elaborate and expensive separate assembly work for one additional stop to the mobility of the insulating layer to restrict.

Conveniently, is the insulating layer for thermal insulation in the area the at least one end of the decoupling element between the layers of a gas-conducting component and a position of a in the decoupling element partially inserted line element arranged. This is it is possible, the insulating layer only directly at the Assemble assembly of the line element on the decoupling by by the insulating layer together with the line element in the decoupling element is inserted. Then then the line element be set on the decoupling element.

advantageously, is a position of the decoupling element as a gas-carrying component, especially as a liner (usually made from a wound Metal hose, in particular a Agraffschlauch consists) or Flame tube formed. The use of a liner increases additionally the damping properties of the decoupling element, whereas the use of a flame tube is a low-loss and causes largely linear behavior of the decoupling element. To increase the damping effect of the liner also be provided with an outer knit.

In usually it is appropriate, at least one location the decoupling element in the form of a metal bellows, in particular having a substantially undulating profile, to ensure a gas-tightness of the decoupling element. The metal bellows can also be designed in several layers, wherein the insulating layer then also between the layers of the metal bellows can be arranged.

to further improvement of Entkoppelelementes as well as for protection the decoupling element against damage from outside, it is advantageous that at least one further layer in the form of a Outer woven or knitted and / or in the form of a ferrule or an end ring is arranged. It is also in the According to the invention, at least one of the further layers at least two-layered is executed. The insulating layer can then also arranged between the at least two layers of the further layer be.

In order to the position of the gas-conducting component by connecting of the conduit element is not damaged and at the same time a streamlined transition of a Gas from the line element in the gas-carrying component can be done, it is advantageous if a location in the range of at least one end formed by a connecting sleeve is located at the gas-conducting component, in particular connecting sleeve and gas-conducting Component via a material, non-positive or positive fit Connection are fixed to each other.

Around the insulating layer on at least one end of the decoupling element To fix it, it is expedient that the insulating layer material, non-positive or positive with at least one other Location in the region of the at least one end of the decoupling element is fixed.

Farther it is advantageous if the insulating layer from the range of at least one end substantially in the axial direction in the Decoupling extends into it. This ensures that the Insulation effect of the insulating layer also in the transition region between the at least one end and the interior of the decoupling element occurs or is improved. It is also within the framework the invention that the insulating layer in the axial direction extends through the entire decoupling element.

Especially it is essential that the insulating layer at least two sections having, which divide the insulating layer in the axial direction, in particular the at least two sections of the insulating layer are each different material composition and / or different radial cross-section have. The subdivision of the insulating layer in at least two Sections allows the insulating layer in different Areas in each case the corresponding structural conditions of the decoupling element adapt. It can depending on the desired insulation The material composition can be varied to the heat loss continue to reduce. Just so can the thickness of the insulating layer accordingly be adapted to better isolate certain areas or fill in any voids.

Appropriately, there is the insulation layer of thermally stable insulating material, thermally resistant composite materials or the like. This guarantees an optimal insulating effect of the insulating layer, at the same time the stability of the decoupling element is improved. In particular mineral fibers, glass wool, rock wool, ceramics or the like are suitable as a thermally stable insulation material, as a thermally stable composite materials are particularly suitable multi-layer aluminum insulation mats, etc.

Especially It is advantageous if the insulating layer substantially consists of air and by spacing two radially adjacent Layers is formed. Spacers may be used for spacing be provided, which in particular arranged on at least one layer are. By using air as an insulating layer are high costs avoided for insulation materials. In addition, can also on the cohesive definition or the arrangement of Stops for limiting the axial mobility of the Insulating layer can be dispensed with. A complex installation of the insulating layer one location is also eliminated.

Further Features and advantages of the present invention will become apparent the following description of an embodiment based on the drawings. Showing:

1 an inventive decoupling with an insulating layer and various embodiments;

2 a decoupling element according to the prior art;

3 a cross section through an inventive decoupling element with an insulating layer.

In 1a H is an inventive decoupling element E in the region of its at least one end 10 shown in axial section. This end area 10 the decoupling element E in the 1a has coaxially arranged layers 1 . 2 . 3 . 4 with respect to the axis of the decoupling element E. In this case, the radially innermost layer is a gas-carrying component 1 For example, formed by a liner or a flame tube. On the radial outside of the gas-conducting component 1 is a brat 2 arranged, which is usually made of metal and helical or ring corrugated and in the end 10 the decoupling element 1 has a region without waves. To protect the bellows 2 is on its radial outer side an outer component in the form of an outer knit or -geflechtes 3 arranged.

To determine the radially inner layers 1 . 2 . 3 is in the end area 10 yet another layer in the form of a ferrule 4 and / or an end ring provided.

Is a conduit element in the form of a connecting pipe 5 Partially inserted into the decoupling element E in the axial direction R, the connecting tube is on the radial inner side 1i the gas-carrying component 1 in the end area 10 arranged the decoupling element E. For fixing the connection pipe 5 At the decoupling element E serves a cohesive connection 6 , which is usually designed in the form of a welded joint and on the radial outside 5A of the connection pipe 5 is arranged. It connects the connecting pipe 5 facing end faces 1S . 2S . 3S . 4S the layers 1 . 2 . 3 . 4 the decoupling element E with the radial outside 5A of the connection pipe 5 ,

In 1a is now an insulating layer according to the invention 7 on the radial inside 1i the gas-carrying component 1 in the end area 10 arranged the decoupling element E. The insulating layer 7 in the end area 10 extends in the axial direction substantially of the cohesive connection 6 up to a step S of the gas-carrying component 1 or a front side facing the interior I 5S of the inserted connection pipe 5 , This can be the front side 7S the insulating layer 7 likewise via the cohesive connection 6 with the other layers 1 . 2 . 3 . 4 the decoupling element E or with the connecting pipe 5 be connected.

Stage S of the gas-carrying component 1 divided continuously or continuously the gas-carrying component 1 in at least two areas with different inner and / or outer diameter. In the corrugated area of the bellows 2 has the gas-carrying component 1 a smaller inner and / or outer diameter than in the end 10 of the decoupling element E. The transition between the different inner and outer diameters takes place substantially linearly. It is also within the scope of the invention that the step S, the gas-carrying component 1 each divided into only two areas with different inner diameter or outer diameter.

In 1b is an analogous structure according to 1a to see. The insulating layer 7 is now on a radial inside 2i of the bellows 2 in the end area 10 arranged the decoupling element E. This is the insulating layer 7 between the gas-carrying component 1 and the bellows 2 that is, between the inside 2i of the bellows 2 and the outside 1A the gas-carrying component 1 arranged.

In 1c is a further embodiment of a decoupling element E according to the invention ge shows, now in the end 10 in addition a connection sleeve 1' is arranged, which is the gas-carrying component 1 to the end area 10 the Entkoppelelementes E binds. The connection sleeve 1' in this case has analogous to the level S of the gas-conducting component 1 a step S 'on. The determination of the gas-carrying component 1 on the connection sleeve 1' takes place via a material, non-positive or positive connection 8th usually by compression or welding. The insulating layer according to the invention 7 is between the outside 1'A the connection sleeve 1' and the inside 2i of the bellows 2 arranged. The length of the axial extent of the insulating layer 7 This corresponds essentially to that of the connection sleeve 1' ,

Similar to 1c is the arrangement of the insulating layer 7 in 1d , The insulating layer 7 is again on the radial inside 2i of the bellows 2 arranged. The decoupling element E has in the end 10 now no connection sleeve 1' more on. As a result, the insulating layer is located 7 at least partially on the outside 5A partially inserted into the decoupling element E connection pipe 5 and at least partially on the outside 1A the gas-carrying component 1 at. The insulating layer 7 is thereby using a material, force or positive connection 8th at the gas-carrying component 1 set and is like in the others 1a C, e-h with respect to their mobility in at least one axial direction through the integral connection 6 limited.

In 1e is the insulating layer 7 on the radial inside 2i a bellows 2 arranged and is located substantially between the position of the gas-conducting component 1 and the bellows 2 , The insulating layer 7 However, in contrast to 1a in the axial direction at least two subregions 7a . 7b on, which have different radial cross-section. The area 7a the insulating layer 7 has a greater wall thickness, as the wall thickness in the area 7b the insulating layer 7 , At the same time, unlike 1a the insulating layer 7 in the axial direction R from the end region 10 of the decoupling element E partially into the interior I of the decoupling element E.

In 1f is different from 1a the bellows 2 at least two layers with a radially inner layer 2a and a radially outer layer 2 B designed. The insulating layer 7 is between the two layers 2a . 2 B of the bellows 2 arranged and is in the radial direction of these two layers 2a . 2 B limited. A limitation on the mobility of the insulating layer 7 in at least one axial direction takes place again by the cohesive connection 6 ,

In the 1g respectively. 1h is an analogous structure of a decoupling element E according to the invention 1b shown. The insulating layer 7 is in 1g now on the radial inside 3i the Aussengstrickes 3 and thus radially between the position of the outer knitted fabric 3 and the location of the bellows 2 arranged in 1h is the insulating layer 7 on the radial inside 4i the ferrule 4 and thus between the position of the ferrule 4 and the location of the outer knit 3 arranged. In both cases, the insulating layer extends 7 in the axial direction substantially to the corrugated region of the bellows 2 and is in terms of their mobility in at least one axial direction through the cohesive connection 6 limited.

In 2 is shown a decoupling element E according to the prior art. The decoupling element E has in the end 10 coaxial layers of a gas-conducting component from the inside to the outside 1 with a step S, a corrugated bellows 2 , an outer knit 3 and a ferrule 4 on, with the individual layers 1 . 2 . 3 . 4 via a common cohesive connection 6 on their faces 1S . 2S . 3S . 4S in the end area 10 the decoupling element E with an outside 5A a in the axial direction R in the decoupling element E partially inserted connection pipe 5 are fixed. An insulating layer 7 is in the end 10 unavailable.

In the 3a . 3b Radial cross sections of a decoupling element E according to the invention are shown.

3a shows a radial cross section according to 1b in the end area 10 the decoupling element E. The radially innermost layer forms the position of the gas-conducting component 1 , Coaxial to it is on the radial outside 1A the gas-carrying component 1 at least partially over the circumference of the decoupling element E an insulating layer 7 arranged by the location of a bellows 2 is limited radially outward. Coaxial with the position of the bellows 2 are again on the radial outer layers of an outer knitted fabric 3 or a ferrule 4 arranged.

In 3b two sections of a radial cross-section of a decoupling element E according to the invention are shown. The insulating layer 7 is between the radial outside 1A the gas-carrying component 1 and the radial inside 2i of the bellows 2 arranged. The bellows 2 has areas B ₁ , B ₂ , in which the bellows 2 has a different radial distance from the axis M of the decoupling element E and thus also different distances with respect to the radially inner layer of the gas-carrying component 1 having. For this reason, gaps Z, Z ₁ , Z _{2 form} , between the radial outer side 1A the gas-carrying component 1 and the radial inside 2i of the bellows 2 in which the insulating layer 7 is arranged. In this case, the thickness or wall thickness of the insulating layer 7 be designed in the different areas B ₁ and B ₂ so that they are the gap Z, the radially between the position of the gas leading the component 1 and the location of the bellows 2 is arranged, form-fitting fills. The insulating layer 7 can be arranged in full and continuously over the entire circumference of Entkoppelelementes E, as shown in the 3b , left side.

On the right side of the 3b is a decoupling element E in the radial cross section accordingly 3b , left side shown. However, now is the position of the bellows 2 in areas B ₁ , B _{2 formed} so that in the areas B _{1 of} the bellows 2 at least with its radial inside 2i directly on the radial outside 1A the location of the gas-carrying component 1 is applied. The in 3b , left side over the entire circumference extending gap Z is now divided by it into different partial spaces Z ₁ , Z ₂ along the circumference of the decoupling element E. The insulating layer 7 is arranged so that it is arranged in the areas B ₂ , in which the partial spaces Z ₁ , Z ₂ by the radial spacing of gas-conducting component 1 and bellows 2 be effected. The location of the insulating layer 7 is then not arranged continuously or continuously over the entire circumference of the decoupling element, but is arranged only in certain areas B ₂ .

In principle, it is within the scope of the invention to provide not only an insulating layer, but a plurality of insulating layers in the region of at least one end of the decoupling element for thermal insulation, for example by combining different embodiments shown for the arrangement of the insulating layer according to the 1 and 3 ,

In summary the present invention offers the advantage that with the help of Insulating layer in the region of the at least one end of the decoupling element a significant reduction in heat radiation in this Range when passing hot exhaust gases from gasoline or diesel engines is achieved. Downstream of the decoupling arranged Catalysts and diesel particulate filters thus achieve faster Operating temperatur. Reduced exhaust emissions or an improved Regeneration of diesel particulate filters is the result.

e

decoupling

1

gas bearing component

1i

radial Inside gas-carrying component

1A

radial Outside gas-carrying component

1S

front gas-carrying component

1'

connecting sleeve

1'i

inside connecting sleeve

1'A

outside connecting sleeve

1'S

front connecting sleeve

2

bellows

2i

radial Inside bellows

2a, 2 B

documents metal bellows

2S

front Location bellows

3

Outside knits

3i

radial Inside outer knit

3S

front Location of outdoor knitwear

4

ferrule

4i

radial Inside end sleeve

4S

front Position end sleeve

5

connecting pipe

5A

radial Outside connection pipe

5S

front connecting pipe

6

cohesive connection

7

insulating

7a, 7b

subregions insulating

7S

front insulating

8th

material- or positive connection

10

The End decoupling

I

Interior decoupling

R

insertion connecting pipe

Z, Z ₁ , Z ₂

interspaces

B ₁ , B ₂

areas

M

axis decoupling

S, S '

step gas-carrying component or connecting sleeve

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10393976 T5 [0005]
• - DE 10339976 T5 [0008]

Claims (15)

Decoupling element (E) for use with exhaust systems and of a substantially hollow cylindrical shape with in particular a circular or approximately oval cross section and with at least one end ( 10 ), which for connecting a line element ( 5 ) to the decoupling element (E) is suitable, and with at least two substantially coaxially arranged layers ( 1 . 1' . 2 . 3 . 4 ), characterized in that in the region of the at least one end ( 10 ) of the decoupling element (E) an insulating layer ( 7 ) is provided for thermal insulation. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) for thermal insulation on a radial inside ( 1i . 1'i . 2i . 3i . 4i ) at least one location ( 1 . 1' . 2 . 3 . 4 ) is arranged. Decoupling element according to Claim 1, characterized in that a line element connected to the decoupling element (E) ( 5 ) via a cohesive connection ( 6 ), in particular via a welded joint, on at least one layer ( 1 . 1' . 2 . 3 . 4 ). Decoupling element according to claim 1, characterized in that a stop for the mobility of the insulating layer ( 7 ) is arranged in at least one axial direction. Decoupling element according to claim 3 and 4, characterized in that the stop by the cohesive connection ( 6 ) is formed. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) for thermal insulation in the region of the at least one end ( 10 ) of the decoupling element (E) between the layers of a gas-carrying component ( 1 ) and a layer of a partially inserted into the decoupling element line element ( 5 ) is arranged. Decoupling element according to claim 4, characterized in that at least one layer of the decoupling element (E) as a gas-carrying component ( 1 ), in particular as a liner or flame tube is formed. Decoupling element according to claim 1, characterized in that at least one layer of the decoupling element (E) as a metal bellows ( 2 ), in particular with a substantially wave-shaped profile. Decoupling element according to claim 1, characterized in that at least one further layer in the form of an outer braid ( 3 ) or knitted and / or in the form of a ferrule ( 4 ) or a ring is arranged. Decoupling element according to claim 1, characterized in that a layer in the region of the at least one end ( 10 ) through a connecting sleeve ( 1' ) formed at the gas-carrying component ( 1 ), in particular connecting sleeve ( 1' ) and gas-carrying component ( 1 ) via a material, non-positive or positive connection ( 8th ) are fixed to each other. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) with material, force or form fit with at least one further layer in the region of the at least one end ( 10 ) of the decoupling element (E) is fixed. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) from the region of the at least one end ( 10 ) extends substantially in the axial direction into the decoupling element (E). Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) at least two sections ( 7a . 7b ) comprising the insulating layer ( 7 ) in the axial direction, wherein in particular the at least two sections ( 7a . 7b ) of the insulating layer ( 7 ) each have different material composition and / or different radial cross-section. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) consists of thermally stable insulation material, thermally stable composite materials or the like. Decoupling element according to claim 1, characterized in that the insulating layer ( 7 ) consists essentially of air and by spacing two radially adjacent layers ( 1 . 1' . 2 . 3 . 4 ) is formed.