EP2522824B1 - Exhaust gas assembly component - Google Patents

Description

The present invention relates to an exhaust system component of an exhaust system for an internal combustion engine, in particular of a motor vehicle, having the features of the preamble of claim 1.

Exhaust system components include, for example, mufflers, catalytic converters, particulate filters, SCR systems, NOX storage systems and any combinations thereof. To reduce the fuel consumption of motor vehicles is trying to reduce the weight of the motor vehicle. This can be done, for example, by using light metals instead of ferrous metals and / or by using plastics instead of metals in order to produce components of the vehicle which are characterized by their low weight. Since plastics have a low temperature resistance to metals, the use of plastics in the field of an exhaust system is associated with great difficulties.

A generic exhaust system component is from the WO 2011/047852 A1 known. It comprises an inner tube made of metal, which is exposed during operation of the exhaust system exhaust gas, a housing made of plastic, which encloses a working space, and an outer tube made of metal, which has two end portions, which is fastened at its first end region on the inner tube, which firmly with the housing is connected and which encloses between its end regions a radially formed between the inner tube and outer tube annulus. In the known exhaust system component, the plastic housing is reduced via an annular disc to the outer tube, wherein the housing may be molded onto the annular disc.

From the WO 2010/025927 A1 an exhaust gas system component is known in which an injection-molded plastic end caps is mounted on a stainless steel sheet, are formed on the spring portions.

Other exhaust system components, in which the housing is attached to the outer tube, are from the EP 1 559 877 A1 , from the US 5,340,952 , from the U.S. 4,993,513 , from the WO 2005/066467 A1 and from the DE 40 33 858 A1 known.

Other exhaust system components in the form of silencers are from the DE 11 2006 000 693 T5 , from the WO 2004/099576 A1 and from the DE 10 2009 031 848 A1 known.

The present invention addresses the problem of finding a way for an exhaust system component to be able to at least partially produce it from plastic.

This problem is solved according to the prinvention by the subject-matter of the independent claim. Vortellhaft embodiments are the subject of the dependent claims.

The invention is based on the general idea, in an exhaust system component, a component that is not directly affected by hot exhaust gases to manufacture plastic and a metallic component, which is also not directly applied by the exhaust, to attach to a metallic component, the can now be acted upon directly by the exhaust gas. By means of this indirect connection of the plastic construction module via a metal component with little thermal load, with the thermally higher loaded metal component, the heat transfer into the plastic component can be significantly reduced. The thermal load of the plastic component remains within half the thermal load limits of the plastic component, whereby the desired fatigue strength for the exhaust system component in hybrid construction can be achieved.

Specifically, it is proposed to equip the exhaust system component with at least one inner tube made of metal, with a housing made of plastic and with at least one outer tube made of metal. The inner tube is exposed to exhaust gas during operation of the exhaust system. In particular, it serves for exhaust gas routing. The housing encloses a working space. The outer tube is attached to the inner tube in a first end region and fixedly connected to the housing in a second end region. Further, between the end portions of the outer tube, a radial between the inner space and the outer tube formed annular space is provided. This design avoids direct contact between the housing and the inner tube, which reduces the thermal load on the housing. The preferably concentric arrangement of the outer tube on the inner tube, such that an annular space is formed, leads to a so-called. Air gap insulation between the outer tube and the inner tube, which significantly reduces the thermal load on the outer tube. Accordingly, the outer tube is significantly cooler compared to the inner tube, which reduces the heat input into the housing.

According to the invention, the housing is molded onto the outer tube. By injecting the plastic onto the outer tube, the second end region of the connecting tube can be embedded in the plastic of the housing, as a result of which, in particular, an intensive positive connection can be achieved. Injecting the Kunststoffbautells to the metal component also inevitably leads to an effective seal, without additional sealing elements must be used.

Is particularly advantageous in the invention that at the second end portion of the outer tube Anspritzkonturen are integrally formed, which is a positive Ver Make bond with the molded housing. For example. These Anspritzkonturen may have openings and / or undercuts that allow an intensive anchoring of the second end portion in the plastic of the housing. The Anspritzkonturen can, for example, lobe-like or tab-like and be configured mehrgliedrig particular. Likewise, several Anspritzkonturen be arranged distributed in the circumferential direction of the outer tube.

The outer tube can according to an advantageous embodiment in the circumferential direction or in the longitudinal direction have a corrugated profile, which provides for a larger surface of the outer tube and thus allows better heat radiation into the environment of the outer tube. In this way, the heat transfer from the inner tube via the outer tube can be reduced to the housing.

Additionally or alternatively, the outer tube may have on its outer side a passive cooling structure, which also provides for an enlarged surface of the outer tube and accordingly supports the heat transfer to the environment.

According to an advantageous development, the cooling structure may have a plurality of annular disk-shaped cooling ribs. Such cooling fins can be individually welded or soldered to the outer tube. Likewise, a radiator block, which has a plurality of such annular disc-shaped cooling fins, from the outside be attached to the outer tube and connected to it. Furthermore, it is possible to design the cooling structure in such a way that it has at least one cooling coil helically wrapped around the outer tube. The cooling coil can also be welded or soldered to the outer tube.

In another advantageous embodiment, a thermally insulating insulating material can be arranged in the annular gap in order to further reduce the thermal stress on the outer tube.

Another embodiment proposes to form a sliding fit between the housing and the inner tube, so that although a support between the housing and inner tube can take place, but relative movements between the housing and inner tube continue to be possible, for example. To allow thermally induced strains without tension. Particularly useful is an embodiment in which the housing carries a sliding bearing, via which the support between the housing and inner tube, so there is no direct contact between the housing and the inner tube. Such a sliding bearing can be realized, for example, by means of Teflon or by means of PEEK or by means of polyimide or by means of a wire mesh. Likewise, combinations of the above materials are conceivable.

In a further embodiment, the exhaust system component may be designed so that the housing is held on the inner tube exclusively via a single such outer tube. In this case, the inner tube does not flow through the exhaust gas during operation of the exhaust system, but serves to connect the exhaust system component to an exhaust pipe of the exhaust system component, which is traversed by the exhaust gas during operation of the exhaust system. The working space of the housing is therefore also not flowed through by the exhaust gas, but is in shunt with the exhaust stream. Connecting the inner pipe to the exhaust pipe can be done directly or indirectly via a corresponding connector, the connector may be designed in particular as a Y-tube and / or clamshell.

According to a development, the exhaust system component may be an active silencer, which is acoustically connected to the exhaust system via the inner tube. In the working space then a loudspeaker of the active silencer is arranged, wherein the working space can also form an anteroom and a rear space for the speaker. The inner tube is used for acoustic coupling and is not flowed through by the exhaust gas of the exhaust system, since the active muffler is connected in shunt to the exhaust gas flowed through the exhaust pipe of the exhaust system. Alternatively, the exhaust system component may be a Helmholtz resonator, which is acoustically connected to the exhaust system via the inner tube. In this case, the working space forms the resonance space of the Helmholtz resonator, while the inner tube forms the resonator neck of the Helmholtz resonator. Also, such a Helmholtz resonator is usually connected in shunt to the exhaust gas flowed through by the exhaust pipe.

According to another advantageous embodiment, the housing may be held on the inner tube via two such outer tubes. In this case, in particular an embodiment is possible in which the inner tube flows through the exhaust gas during operation of the exhaust system. For example. The exhaust system component can then be a passive silencer, in which case the inner pipe can be perforated and / or interrupted. About the perforation or interruption of the inner tube, the acoustic coupling between the exhaust stream and the working space of the housing takes place. The working space can serve as an absorption space and / or as a reflection space and / or as an expansion space and / or as a resonance chamber, depending on the type and embodiment of the muffler. If the working space serves as the absorption space, it can in particular also be filled with an absorption material.

According to an advantageous embodiment, attachment points, with the aid of which the exhaust system component can be attached to a support structure, in particular to a body of the vehicle, can be arranged on the outer tube. Usually, such fastening points are formed on the housing. In the hybrid exhaust system component presented here, however, the arrangement of such attachment points on the metallic outer tube is preferred in order to reduce the mechanical load on the housing.

In particular, this can be arranged on the respective outer tube at least one fastening element of a fastening device, by means of which the exhaust system component can be fastened to a support structure. The respective fastening element can be welded or soldered to the outer tube. The fastener may be a tab, a bracket or an angle. The support structure is expediently a vehicle body or an underbody of the vehicle. In particular, the fastening of the exhaust gas system component to the support structure takes place exclusively via the outer tube, as a result of which the housing is mechanically relieved.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained not only in the combination specified, but can also be used in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Fig. 1

ein Längsschnitt durch einen Teil einer Abgasanlagenkomponente,

Fig. 2

eine Axialansicht der Abgasanlagenkomponente entsprechend einer Blickrichtung II in Fig.1,

Fig. 3

ein Längsschnitt durch eine andere Abgasanlagenkomponente, in einem anderen Bereich,

Fig. 4

eine Axialansicht der Abgasanlagenkomponente entsprechend einer Blickrichtung IV in Fig. 3,

Fig. 5

ein halber Längsschnitt durch eine Abgasanlagenkomponente im Bereich eines Außenrohrs,

Fig. 6

ein halber Längsschnitt wie in Fig. 5, jedoch bei einer anderen Ausführungsform,

Fig. 7

ein Querschnitt der Abgasanlagenkomponente entsprechend Schnittlinien VII in Fig. 6,

Fig. 8 und 9

jeweils einen halben Längsschnitt der Abgasanlagenkomponente im Bereich eines Außenrohrs bei verschiedenen Ausführungsformen,

Fig. 10

eine Seitenansicht einer Abgasanlagenkomponente bei einer weiteren Ausführungsform,

Fig. 11 und 12

stark vereinfachte Längsschnitte einer Abgasanlage im Bereich einer Abgasanlagenkomponente bei verschiedenen Ausführungsformen.

Show, in each case schematically,

Fig. 1

a longitudinal section through a part of an exhaust system component,

Fig. 2

an axial view of the exhaust system component according to a line of sight II in Fig.1 .

Fig. 3

a longitudinal section through another exhaust system component, in another area,

Fig. 4

an axial view of the exhaust system component according to a viewing direction IV in Fig. 3 .

Fig. 5

a half longitudinal section through an exhaust system component in the region of an outer tube,

Fig. 6

a half longitudinal section as in Fig. 5 but in another embodiment,

Fig. 7

a cross section of the exhaust system component according to section lines VII in Fig. 6 .

8 and 9

each a half longitudinal section of the exhaust system component in the region of an outer tube in various embodiments,

Fig. 10

a side view of an exhaust system component in a further embodiment,

FIGS. 11 and 12

highly simplified longitudinal sections of an exhaust system in the region of an exhaust system component in various embodiments.

According to the FIGS. 1 to 12 comprises an exhaust system component 1, which is for installation in one only in the Figures 11 and 12 partially shown exhaust system 2 an internal combustion engine, preferably a motor vehicle, is provided, at least one inner tube 3, at least one housing 4 and at least one outer tube 5. The inner tube 3 is made of metal and is exposed during operation of the exhaust system 2 exhaust gas of the internal combustion engine. In this case, the inner tube 3 does not necessarily have to be flowed through by the exhaust gas. The housing 4 is made of a plastic and encloses a working space 6. The outer tube 5 is again made of metal and is fixed in a first end portion 7 on the inner tube 3, z. B. by means of a welded joint 8. The outer tube 5 is fixedly connected to the housing 4 in a second end region 9 remote from the first end region 7. Furthermore, the outer tube 5 is arranged or dimensioned with respect to the inner tube 3 such that it encloses, between its end regions 7, 9, an annular space 10 formed radially between inner tube 3 and outer tube 5 in the circumferential direction. This annular space 10 creates an air gap insulation between inner tube 3 and outer tube. 5

The relative directions, such as "circumferential direction" and "radial" or "axial", in this context relate to a longitudinal central axis 15 of the inner tube 3.

In the embodiments of the FIGS. 1 to 12 the housing 4 is arranged contactless with respect to the inner tube 3, so that the housing 4 is connected exclusively to the inner tube 3 via the outer tube 5.

Suitably, the housing 4 is molded onto the outer tube 5, whereby the second end portion 9 is embedded in the plastic of the housing 4. In particular, the plastic of the housing 4 can thus comprise the second end region 9 of the outer tube 5 on both sides, ie radially inward and outward.

At the second end region 9 of the outer tube 5, injection-molded contours 11 are advantageously integrally formed, which are designed so that they form a positive connection with the molded-on housing 4. The Anspritzkonturen 11 may, for example, be several distributed in the circumferential direction arranged tabs 12, according to Fig. 2 single-membered or according to Fig. 4 can be multi-membered. In the Anspritzkonturen 11 breakthroughs 13 may be formed, which are penetrated by the molded plastic. The Anspritzkonturen 11 can according to Fig. 3 be stepped to form undercuts 14 which are positively enclosed by the plastic.

At the in Fig. 5 In the embodiment shown, the outer tube 5 has a corrugated profile in the longitudinal direction, whereby the outer tube 5 is designed like a bellows. In the in the FIGS. 6 and 7 In the embodiment shown, the outer tube 5 has a corrugated profile in the circumferential direction. The respective corrugated profile of the outer tube 5 increases the surface of the outer tube 5, which favors the heat transfer from the outer tube 5 to the environment.

In the embodiments of the FIGS. 8 to 11 the outer tube 5 is provided on its outside with a passive cooling structure 16 in order to improve the heat dissipation to the environment. Corresponding Fig. 8 For example, the cooling structure 16 may have a plurality of annular disk-shaped cooling ribs 17, which in particular may be individually welded or soldered to the outer pipe 5. At the in Fig. 9 In the embodiment shown, the cooling structure 16 comprises at least one cooling coil 18, which spirally winds the outer tube 5. Also the cooling coil 18 is suitably welded to the outer tube 5 or soldered thereto.

At the in Fig. 12 1, a thermally insulating insulating material 19 is introduced into the annular gap 10 in order to reduce the heat transfer from the inner tube 3 to the outer tube 5. Furthermore, at the in Fig. 12 shown embodiment, a sliding seat 20 is formed between the housing 4 and the inner tube 3, so that a direct or indirect support between the housing 4 and inner tube 3 can take place. Appropriately, however, a sliding bearing 21 is provided for the realization of the sliding seat 20, which is particularly supported by the housing 4. The sliding bearing 21 can be realized, for example, during injection molding of the housing 4 in the form of an insert inserted into the injection mold, which is integrally molded into the housing 4 during injection molding of the housing 4. The slide bearing 21 may be formed, for example, from Teflon, PEEK, polyimide, wire mesh. Additionally or alternatively, according to Fig. 12 In addition, a radial bearing 22 may be provided which allows radial support between the inner tube 3 and outer tube 5. Also, this radial bearing 22 may be made of Teflon or PEEK or polyimide or wire mesh. Again, it is possible to consider the radial bearing 22 during injection molding of the housing 4 already in the form of an insert in the mold.

In the embodiments of the Figures 11 and 12 the housing 4 is held exclusively on a single outer tube 5 on the inner tube 3. The inner tube 3 is not traversed by the exhaust gas in these embodiments during operation of the exhaust system 2. An exhaust gas flow is in the Figures 11 and 12 indicated by an arrow 23. The inner tube 3 is connected to an exhaust pipe 24 of the exhaust system 2, which is traversed by the exhaust gas during operation of the exhaust system 2. At the in Fig. 11 In the embodiment shown, the connection of the inner tube 3 to the exhaust pipe 24 takes place directly. At the in Fig. 12 shown embodiment a connection piece 25 is provided, via which the inner tube 3 is connected to the exhaust pipe 24. The connector 25 is in the example of Fig. 12 designed as Y-tube and double-shelled.

The exhaust system component 1 can be, for example, an active silencer, which can also be referred to below as 1 and which is acoustically connected to the exhaust system 2 via the inner tube 3. According to Fig. 11 can the active muffler 1 in the working space 6 of the housing 4 include a speaker 26, wherein in the working space 6 also an antechamber 27 and a rear space 28 of the speaker 26 are included. The inner tube 3 is not flowed through, but allows the acoustic coupling between the muffler 26 and the exhaust pipe 24th

Alternatively, the exhaust system component 1 may also be a Helmholtz resonator, which may also be referred to below as 1 and which is acoustically connected to the exhaust system 2 via the inner tube 3. Corresponding Fig. 12 The inner tube 3 then forms a resonator neck of the Helmholtz resonator 1. Again, the inner tube 3 is not flowed through by the exhaust gas, but allows the vibration coupling between the resonance chamber 6 and the exhaust pipe 24th ,

At the in Fig. 10 In the embodiment shown, the housing 4 is held on the inner tube 3 via two outer tubes 5. In this case, the inner tube 3 may be traversed by the exhaust gas during operation of the exhaust system 2. A corresponding exhaust gas flow is also in Fig. 10 indicated by an arrow 23. Suitably, the exhaust system component 1 may be configured in such a case as a passive muffler. The inner tube 3 is provided within the housing 4, for example, with an interruption 29 and / or with a perforation 30, whereby an acoustic coupling between the interior of the inner tube 3 and the working space 6 of the housing 4 is made possible. The working space 6 can serve as an absorption space and / or as a reflection space and / or as an expansion space and / or as a resonance space. In particular, the working space 6 can be filled with an absorption material.

According to the Figures 1 and 2 For example, in a preferred embodiment, at least one fastening element 31 of a fastening device 32 can be fastened to the respective outer tube 5, with the aid of which the exhaust system component 1 can be fastened to a supporting structure, not shown here. For example. the fastening element 31 is designed here in the form of a tab, which can be fixed by means of a welded joint 33 on the outer tube 5. For example, a screw connection of the exhaust system component 1 to the support structure can be realized via the tab 31. The support structure can be, for example, a vehicle body, in particular an underbody, of the vehicle. Suitably, the exhaust system component 1 is fixed exclusively on such fastening elements 31 on the respective support structure, which are attached to the outer tube 5, so that in particular an additional mechanical load of the housing 4 can be avoided.

Claims (15)

1. Exhaust system component of an exhaust system (2) for an internal combustion engine, in particular of a motor vehicle, said component comprising:

   - an inner pipe (3) made of metal, which is exposed to exhaust gas during operation of the exhaust system (2)

   - a housing (4) made of plastics material, which encloses a working chamber (6),

   - at least one outer pipe (5) made of metal, which comprises two end regions (7, 9), is attached to the inner pipe (3) by the first end region (7) thereof, is rigidly connected to the housing (4), and encloses an annular gap (10), which is formed radially between the inner pipe (3) and the outer pipe (5), between the end regions (7, 9) of said outer pipe,
   characterised in that

   - the second end region (9) of the outer pipe (5) is rigidly connected to the housing (4),

   - the housing (4) is moulded onto the outer pipe (5),

   - moulding contours (11) are integrally formed on the second end region (9) of the outer pipe (5), which contours form an interlocking connection with the moulded-on housing (4).
2. Component according to claim 1, characterised in that the housing (4) does is not in direct contact with the inner pipe (3) in the second end region (9) of the outer pipe (5)
3. Component according to either claim 1 or claim 2, characterised in that at least one such moulding contour (11) is formed by an opening (13).
4. Component according to any of claims 1 to 3, characterised in that at least one such moulding contour (11) is formed by an undercut (14).
5. Component according to any of claims 1 to 4, characterised in that the inner pipe (3) and the outer pipe (5) are arranged concentrically relative to each other.
6. Component according to any of claims 1 to 5, characterised in that

   - the outer pipe (5) has an undulating profile in the circumferential direction, or

   - the outer pipe (5) has an undulating profile in the longitudinal direction.
7. Component according to any of claims 1 to 6, characterised in that the outer side of the outer pipe (5) comprises a passive cooling structure (16).
8. Component according to claim 7, characterised in that

   - the cooling structure (16) comprises a plurality of annular-disc-shaped cooling ribs (17), and/or

   - the cooling structure (16) comprises at least one cooling coil (18) which is wound helically around the outer pipe (5).
9. Component according to any of claims 1 to 8, characterised in that a heat-insulating insulation material (19) is arranged in the annular gap (10).
10. Component according to any of claims 1 to 9, having a sliding fit (20) between the housing (4) and the inner pipe (3).
11. Component according to any of claims 1 to 10, characterised in that

    - the housing (4) is held on the inner pipe (3) only by means of a single such outer pipe (5),

    - exhaust gas does not flow through the inner pipe (3) during operation of the exhaust system (2) and said inner pipe is provided for connection to an exhaust-gas pipe (24) of said exhaust system (2), through which exhaust-gas pipe exhaust gas flows during operation of said exhaust system (2).
12. Component according to claim 11, characterised in that

    - the exhaust system component (1) is an active silencer, which is acoustically connected to the exhaust system (2) via the inner pipe (3), or

    - the exhaust system component (1) is a Helmholtz resonator, which is acoustically connected to the exhaust system (2) via the inner pipe (3).
13. Component according to any of claims 1 to 10, characterised in that

    - the housing (4) is held on the inner pipe (3) by means of two such outer pipes (5),

    - exhaust gas flows through the inner pipe (3) during operation of the exhaust system (2).
14. Component according to claim 13, characterised in that the exhaust system component (1) is a passive silencer, the inner pipe being (3) perforated and/or interrupted.
15. Component according to any of claims 1 to 14, characterised in that at least one attachment element (31) of an attachment device (32) is arranged on each outer pipe (5), by means of which attachment element the exhaust system component (1) can be attached to a supporting structure.

Images