EP3199772B1 - Sound generator for an exhaust system - Google Patents

Description

The present invention relates to a silencer for an exhaust system, such as an exhaust system, with which the generated in an internal combustion engine in a vehicle combustion exhaust gases are discharged to the environment.

From the DE 10 2005 026 376 A1 Such a silencer is known in which inlet pipes serving as exhaust ducts are connected in a first connection region to a wall provided in the interior of the silencer and are connected in a second connection region to an outer wall enclosing the interior of the silencer. In the first connection region, the inlet tubes are formed with an annular shape which can completely pass through in the circumferential direction or can have a plurality of ring segments. For connection to this first connection region, the wall has, in a first counter-connection region, a receiving opening, formed in a tubular extension, for a respective inlet tube. The tube-like projection has a bead-like formation on its inner peripheral region into which the ring-like formation of the first connection region can be positioned to engage or engage with the wall.

The DE 10 2010 015 322 B4 discloses a muffler for an exhaust system in which an exhaust pipe serving as an inlet pipe has an annular recess in a first connection region. In a wall to be connected to the exhaust gas guide pipe in this first connection region, a receiving opening for the exhaust gas guide pipe is formed with a plurality of tabs which follow one another in the circumferential direction and surround the receiving opening. For connecting the exhaust gas guide tube to the wall, a conical insertion end of the exhaust gas guide tube into the receiving opening inserted. The tabs are deflected in the direction of movement of the exhaust duct until they engage in the annular shape in the exhaust duct or engage. In an alternative embodiment, an annular recess for receiving the tabs between two axially spaced apart positioned annular formations of the exhaust pipe is formed.

From the US 1 968 456 A a muffler is known in which the two end walls of a muffler housing are connected to this outside subsequent pipes by threaded engagement.

A silencer according to the preamble of claim 1 is known from US 2007/051557 A1 known.

It is the object of the present invention to provide a muffler for an exhaust system, in which an exhaust pipe can be connected in a simple, yet stable manner with a wall.

According to the invention, this object is achieved by a silencer for an exhaust system according to claim 1. This comprises an outer wall as well as an outer end wall of the outer wall and an outer wall of the interior of the muffler outwardly delimiting end walls an exhaust duct and a in a first connection region of the exhaust duct with this Wall connected by thread-like engagement.

By creating a thread-like engagement between the exhaust pipe and the wall to be joined to a stable, easy to manufacture and a relative movement between the two components exhaust pipe and wall substantially not permitting compound is achieved.

Since a completely gas-tight connection between these two parts can not be ensured by the preparation of the thread-like engagement between the exhaust pipe and the wall, the wall is arranged between two interior dividing the interior into individual space areas and firmly connected to the outer walls intermediate walls and thus firmly connected inner wall , And in a second connection region, the exhaust pipe is connected to a further wall, for example an outer wall. Thus, the connecting pipe in the same two longitudinal areas, preferably each near a pipe end of the same, stably connected to other components or with walls of the muffler, so that even stronger forces from the outside can not lead to an undesirable deformation or displacement of the exhaust pipe.

In order to provide this thread-like engagement between the exhaust pipe and the wall, an external thread formation is advantageously provided on the exhaust pipe. This can be provided, for example, by a helical manner in the direction of a tube longitudinal axis of the exhaust gas guide tube, that is to say essentially in the form of a spiral.

In order to be able to produce a stable engagement with the wall, it is proposed that the formation between a thread in the direction of the pipe longitudinal axis successive molding areas provides. The engaging in this thread wall is thus stable by the thread between them in the axial direction forming regions in the axial direction, advantageously kept substantially without movement play.

A substantially uniform and stable connection between the exhaust gas duct pipe and the wall over the circumference can be achieved if the molding for providing at least one turn, preferably at least two turns, is circumferentially substantially continuous without interruption. As an alternative to a circumferentially continuous uninterrupted molding, which can provide a correspondingly uninterrupted circumferential thread, can also in Circumferentially be provided subsequent molding segments, which provide a corresponding circumferentially segmented thread.

An embodiment which is advantageous on account of the simple production can provide that the formation is formed with a substantially constant thread pitch radius or / and thread bottom radius.

In an alternative embodiment, the formation may be formed with decreasing in the direction of a pipe end of the exhaust pipe guide thread pitch radius. This leads to an at least on the outside of the exhaust pipe tapering, preferably substantially conically tapered configuration which simplifies the defined positioning of the exhaust pipe with respect to the wall in the direction of the tube longitudinal axis when making the thread-like engagement with the wall.

In order to provide the thread-like engagement with the first connection region, a first counter-connection region formed on the wall may comprise an exhaust gas pipe receiving opening and surrounding a plurality of engagement plates deflectable in the direction of the pipe longitudinal axis.

In order to enable the shape matching of the wall in its first counter-connection region to the thread-like structure of the exhaust guide tube in a simple manner when producing the thread engagement, it is proposed that circumferentially successive engagement tabs through cuts or recesses, preferably with a substantially radial extension direction with respect to the tube longitudinal axis, are separated from each other.

The tabs may be threadedly engaged with the male thread formation by screwing the exhaust gas guide tube into the receiving opening.

In order to be able to ensure a gas-tight closure in particular in the area of the connection to the further wall, it is proposed that in the second connection region the exhaust-gas guide tube is connected to the further wall in a material-locking manner, preferably by welding.

The exhaust pipe or / and the wall can be constructed of sheet metal material, so that it is possible in a simple manner to bring by known deformation machining these components in their desired shape or configuration.

The invention further relates to an exhaust system for a vehicle with at least one silencer constructed according to the invention.

Fig. 1

eine perspektivische Teil-Ansicht eines Schalldämpfers;

Fig. 2

eine Schnittansicht des Schalldämpfers der Fig. 1, geschnitten längs einer Linie II-II in Fig. 3;

Fig. 3

eine Schnittansicht des Schalldämpfers der Fig. 1, geschnitten längs einer Linie III-III in Fig. 2;

Fig. 4

eine Schnittansicht des Schalldämpfers der Fig. 1, geschnitten längs einer Linie IV-IV in Fig. 3;

Fig. 5

eine vergrößerte Detailansicht eines durch Gewindeeingriff mit einer Wandung verbundenen Abgasführungsrohrs;

Fig. 6

eine der Fig. 2 entsprechende Darstellung einer alternativen Ausgestaltungsart.

The present invention will be described below in detail with reference to the accompanying drawings. It shows:

Fig. 1

a partial perspective view of a muffler;

Fig. 2

a sectional view of the muffler of Fig. 1 , cut along a line II-II in Fig. 3 ;

Fig. 3

a sectional view of the muffler of Fig. 1 , cut along a line III-III in Fig. 2 ;

Fig. 4

a sectional view of the muffler of Fig. 1 , cut along a line IV-IV in Fig. 3 ;

Fig. 5

an enlarged detail view of an exhaust guide tube connected by threaded engagement with a wall;

Fig. 6

one of the Fig. 2 corresponding representation of an alternative Ausgestaltungsart.

The Fig. 1 to 5 show a first embodiment of a generally designated 10 muffler for an exhaust system of an internal combustion engine. It should be noted that the muffler is shown in these figures only with its essential components for explaining the principles of the present invention.

The muffler 10 comprises an outer wall 12 preferably formed of sheet metal material and together with the outer wall 12 an inner space 14 of the muffler 10 delimiting or subdividing into individual space areas intermediate walls 16, 18. Corresponding walls can also at the end of the example formed with elliptical cross-section outer wall 12th be provided to the interior 14 in the axial direction to limit the outside. It should be noted that the outer wall 12 with the intermediate walls 16, 18 and the Endwandungen not shown, in particular for producing a gas-tight seal preferably material fit, z. B. by welding, is firmly connected.

The muffler 10 further comprises an exhaust gas duct 20, which may be an inlet pipe in the example shown. In a hereinafter explained in more detail and provided in the region of a first pipe end 22 first connection region 24, the exhaust pipe 20 is connected to a wall 26, which forms an inner wall in the example shown. The wall 26 is arranged in the example shown between the two intermediate walls 16, 18 and fixedly connected to these, for example by welding.

In a second connecting region 30 formed at a second tube end 28, the exhaust gas guide tube is connected to the outer wall 12. In the second connection region 30, the exhaust gas guide tube 20 is substantially cylindrical and inserted into a cylindrical neck 32, for example, of the outer wall 12 that has been shaped outwards. By a circumferentially preferably interruption-free circumferential weld 33, the exhaust gas guide tube 20 is gas-tightly connected to the outer wall 12 by material closure in the second connection region 30.

In the second connection region 24, the exhaust gas guide tube 20 is formed with an external thread formation 34. In particular, when the exhaust gas guide tube 20 is formed of sheet material and thus relatively easily deformable, the external thread formation can be provided by forming a circumferentially around a pipe longitudinal axis L _{R of} the exhaust guide tube 20 helically encircling formation 36. This can be formed for example by means of conventional forming techniques, such as rolling, and thus leads to a substantially undulating structuring of the exhaust gas guide tube 20 in the first connection region 24.

In the exemplary embodiments illustrated, the formation 36 is designed to protrude radially outwardly with respect to the tube longitudinal axis L _R via the otherwise substantially cylindrical exhaust-gas guide tube 20, which is achieved by forming radially outward and thus forming locally radially expanded regions. Alternatively, the molding 36 could at least partially by forming radially inward, so be formed on the otherwise substantially cylindrical exhaust guide tube 20 radially inwardly projecting.

In the in the Fig. 1 to 5 illustrated embodiment, the helically circulating formation 36 has over the axial length of the first connection portion 24 substantially constant thread pitch radius Rs, so that the helically circulating formation has substantially a helical winding structure. Only where the radial projection height increases or decreases at the beginning or at the end of this configuration 36 which is configured in the shape of a meander does the thread pitch radius Rs increase or decrease accordingly.

In the direction of the tube longitudinal axis L _R successive molding portions 36a and 36b, which are of course provided by the single, preferably uninterrupted circumferential shaping 36, a thread 38 is formed. In order to design the thread 38 preferably also over the entire circumference of the exhaust guide tube 20 interruption-free, in the illustrated embodiment example, the formation 36 can be provided with at least two turns. It should be noted that in the embodiment of the molding 36 by forming radially inward of the thread in the region of the molding itself is formed and the above-mentioned molding areas, between which a respective thread is formed, are provided by not substantially radially inwardly deformed areas the exhaust duct 20

The Fig. 4 shows that on the wall 26 in a first counter-connection region 40, an exhaust gas pipe receiving opening 42 for receiving the exhaust pipe 20, in particular of the first connecting portion 24 thereof is provided. The exhaust pipe receiving hole 42 is surrounded by a plurality of circumferentially consecutive engaging tabs 44. In the illustrated embodiment, each four approximately such an engagement tabs 44 are provided extending over an angular range of 90 °. The circumferentially adjacent or successive engagement tabs 44 are separated from each other in the circumferential direction. In the exemplary embodiment shown, a defined spacing-introducing recesses 46 are provided, which extend substantially radially with respect to the tube longitudinal axis L _R and terminate in their radially outer regions in respective circular extensions 48.

As well as the exhaust pipe 20 is advantageously also the wall 26 constructed of sheet material. The wall 26 is thus deformable, in particular in the region of the engagement straps 44, so that they can be deflected or bent in the direction of the tube longitudinal axis L _R with a corresponding load, in particular distributed over the circumference, deflected or bent to varying degrees.

To produce the thread-like engagement of the first connection region 24 or the external thread formation 34 with the first counter-connection region 40, the exhaust-gas guide tube 20 is introduced with its tube end 22 into the exhaust-gas tube receiving opening 42. In this state, the wall 26, in particular in the region of the first mating connection region 40, is designed substantially planar with its engagement lugs 44. The exhaust guide tube 20 is pressed against the tabs 44 with axial pressure, so that by the in Fig. 3 recognizable beginning 50 of the formation 36 one of the engaging tabs 44 axially loaded and deflected in the direction of insertion of the exhaust duct 20. If the exhaust guide tube 20 is rotated in this process, the beginning 50 of the molding 36 moves toward one of the recesses 46. The engaging in this state by the shaping 36 engaging tab 44 is relative to the circumferentially following and not loaded in the axial direction and accordingly also not deflected engaging tab 44 axially displaced or bent. With continuing rotation of the exhaust guide tube 20, the beginning 50 of the molding 36 then moves behind the axially not deformed or deflected engagement tab 44 so that it enters the thread 38. Continued rotational movement or screwing movement of the exhaust gas guide tube 20 results in successive engagement of all the engaging tabs 44 in the thread 38 until, finally, an over the entire circumference continuous thread-like engagement between the first connecting portion 24 on the exhaust pipe 20 and the first counter-connecting portion 40 at the wall 26 is made.

In this state, the first mating connection region 40, in particular in the radially inner region of the engagement lugs 44, is adapted in its shape to the helically circulating formation 36 and the corresponding helically circulating thread 38. This means that each engaging in the thread 38 engaging tabs 44 viewed in the circumferential direction twisted or different axial deflection.

After the exhaust guide tube 20 has been connected by screwing with the wall 26 in the manner described above, it can be firmly connected in its second connection region 30 with the outer wall 12 in the manner previously described also in the manner described above Vibrations a detachment of the first connection area 24 from the first counter-connection area 40 can not occur.

In the manner described above, the exhaust pipe 20 can be connected to the wall 26 in the interior of the muffler 10 in a simple manner stable, so that the construction of an exhaust system in its second connection area with another pipe to be connected exhaust pipe 20 even under heavy load is held stable in the muffler 10. Preferably, the shaping of the helically circulating shaping 36 is such that between two axially successive forming regions 36a, 36b, such a gap or the thread 38 is formed with such width that the wall 26 with its first counter-connection region 40 in Essentially without axial movement play is added. A slight axial movement play can be compensated or can Therefore, do not lead to vibration or rattling noises, since due to the deformation of the engaging tabs 44 for insertion of the same in the thread 38, these bias against the formation 36.

A modified embodiment also utilizing the principles of the present invention is disclosed in U.S. Pat Fig. 6 shown. The structure corresponds essentially to the previously described. A substantial difference is that the exhaust guide tube 20 is formed in its also the first connecting portion 24 providing length range such that the thread crest radius Rs decreases towards the tube end 22 back. This can be achieved for example by conical configuration or conical deformation of the exhaust pipe 20. Thus, in this embodiment, the helically circulating formation 36 has a spiral-like structure tapering at an acute angle W.

For connecting the exhaust gas guide tube 20 to the wall 26, the first connection portion 36 is inserted into the exhaust gas guide tube receiving opening 42 in the manner described above and made by rotating the thread-like engagement. Due to the increasing thread pitch radius and the correspondingly increasing thread radius increases in a continued rotational movement of the exhaust pipe 20, the strength of the friction interaction between the wall 26 and the exhaust pipe. If a defined torque is exerted on the exhaust-gas guide tube 20 during this process, then a defined screw-in depth of the first connection region 24 into the first counter-connection region can be achieved.

The above-described design principles for producing a thread-like engagement between an exhaust pipe and a wall of a muffler can also be realized in other ways. Thus, it is not necessary to provide a circumferential circumferential direction without deformation, radially outward or inward, to provide the external thread formation. Also in the circumferential direction discrete, so thus spaced apart molding segments such a helical circumferential shaping can be used to build up an external thread formation. Between two axially adjacent segments can be provided in such a configuration in each case a segment of a thread, in which then the engaging tabs of the first counter-connecting portion can be positioned engaging. The number of tabs provided on the first counter-connection region can also be varied. There may be more or fewer than four tabs. When using only two tabs and a greater circumferential spacing thereof to each other, a pseudo-sliding seat can be realized.

As a result of the engagement lugs resting on the molding under pretension, a contact which largely prevents gas leakage is produced. Only where the tabs are separated by the recesses in the circumferential direction and in the region of the circular extensions at the radially outer ends of the recesses a slight gas leakage may occur, which is irrelevant to the functionality of the muffler.

Claims (15)

1. Muffler for an exhaust system, comprising an outer wall (12) and end walls provided in end regions of the outer wall delimiting an inner space (14) of the muffler (10) to the exterior together with the outer wall (12), further comprising an exhaust gas duct pipe (20) and a wall (26) connected to the exhaust gas duct pipe (20) in a first connection area (24) thereof by means of thread-like meshing, wherein the exhaust gas duct pipe (20) is connected to another wall in a second connection area (30), characterized in that the wall (26) is an inner wall arranged between two intermediate walls (16, 18) dividing the inner space (14) into individual spatial areas fixedly attached to the outer wall (12) which is fixedly attached to the latter.
2. Muffler in accordance with claim 1, characterized in that the exhaust gas duct pipe (20) is configured with an outer threaded formation (34) in the first connection area (24).
3. Muffler in accordance with claim 2, characterized in that the outer threaded formation (34) is provided by a formation (36) extending helically along a longitudinal axis (L_R) of the exhaust gas duct pipe (20).
4. Muffler in accordance with claim 3, characterized in that the formation provides a thread pitch (38) between formation areas (36a, 36b) following one another in the direction of the pipe longitudinal axis (L_R).
5. Muffler in accordance with claim 3 or 4, characterized in that the formation (36) is configured as essentially extending without interruption for providing at least one winding, preferably at least two windings, in the circumferential direction.
6. Muffler in accordance with claim 3 or 4, characterized in that the formation (36) comprises a plurality of formation segments following one another in the circumferential direction.
7. Muffler in accordance with one of the claims 4-6, characterized in that the formation (36) is configured with an essentially constant thread apex radius (R_S) or/and thread pitch bottom radius (R_B).
8. Muffler in accordance with one of the claims 4-6, characterized in that the formation (36) is configured with a thread apex radius (Rs) or/and thread pitch bottom radius (R_B) decreasing towards an end (22) of the exhaust gas duct pipe (20).
9. Muffler in accordance with one of the claims 1-8, characterized in that a first counter-connection area (40) formed on the wall (26) for the thread-like meshing with the first connection area (24) comprises an exhaust gas duct pipe receiving opening (42) and a plurality of meshing brackets (44) deflectable in the direction of the pipe longitudinal axis (L_R) enclosing this receiving opening.
10. Muffler in accordance with claim 9, characterized in that meshing brackets (44) following one another in the circumferential direction are separated from one another by notches or recesses (46), preferably with an essentially radial direction of extension in relation to the pipe longitudinal axis (L_R).
11. Muffler in accordance with claim 2 and claim 9 or 10, characterized in that the brackets (44) are in thread-like meshing with the outer threaded formation (34).
12. Muffler in accordance with one of the claims 1-11, characterized in that the exhaust gas duct pipe (20) is connected to the outer wall (12), in a second connection area (30).
13. Muffler in accordance with claim 12, characterized in that the exhaust gas duct pipe (20) is connected to the other wall integrally, preferably by welding, in the second connection area (30).
14. Muffler in accordance with one of the claims 1-13, characterized in that the exhaust gas duct pipe (20) or/and the wall (26) is constructed from sheet metal material.
15. Exhaust system for a vehicle, comprising at least one muffler (10) in accordance with one of the above claims.

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