EP2354483B1 - Exhaust muffler - Google Patents

Description

The present invention relates to a silencer for an exhaust system of an internal combustion engine, in particular of a motor vehicle, with the features of the preamble of claim 1. Furthermore, the invention relates to an associated manufacturing method.

Silencers are divided with respect to the production of their circumferentially closed circumferential shell in two production types, namely silencer in shell construction and silencer in coil construction. While in the shell construction two deep-drawn sheets are joined together at the edge, in the winding construction a sheet is wound around a core and closed. Subsequently, a silencer insert the front side, that is inserted axially into the wound shell and two end plates are attached to the opposite axial ends frontally or used and with the jacket, z. B. by folding, connected.

In the case of a transverse muffler, in particular in the case of a transverse muffler, at least one pipe, in particular an inlet pipe, is arranged laterally so that it extends through the mantle into the interior of the muffler. This is problematic in connection with the winding construction, since this laterally arranged pipe can be mounted only after the insertion of the muffler insert. Because to be able to reliably absorb the forces occurring during operation, it is necessary to support the laterally inserted through the jacket tube both on the jacket and on the inner muffler insert. This support on the muffler insert However, in connection with the winding construction due to the reduced accessibility is difficult to achieve.

From the WO 2006/131165 A1 a muffler of the type mentioned is known. It comprises two end faces facing away from one another, a jacket which is closed in the circumferential direction, at least one muffler insert, at least one inlet pipe and at least one outlet pipe. At least one of the tubes extends through the jacket into the silencer interior. This tube is also attached to the jacket. In the known muffler this pipe is also attached to the muffler insert, by mechanical forming. The attachment of the laterally guided by the jacket pipe on the muffler insert takes place in the known muffler z. Example, in that a Aufweitwerkzeug is introduced into the tube, with which the tube in the region of a bottom of the muffler insert, through which the tube is inserted, is expanded, such that the tube is pressed in a positive fit with the bottom in the radial direction.

The present invention is concerned with the problem of providing a muffler of the type mentioned an improved embodiment, which is characterized in particular by a simplified manufacturability.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The invention is based on the general idea, the tube, which protrudes through the jacket into the silencer interior, at its inner end with a cone to be used to support the pipe on the muffler insert cooperates in the assembled state with a formed on the muffler insert counter cone. Due to the cone engaging in the counter-cone, a positive-locking support between the pipe and the muffler insert results radially and axially with respect to the axial direction of the pipe. Both the cone and the counter cone can be realized comparatively easily. Likewise, the positive engagement of the cone in the counter-cone during assembly can be easily made. In the assembled state results for the laterally mounted pipe sufficient support, namely on the one hand on the jacket and on the other hand on the cooperating with the counter cone cone on the muffler insert. Thus, a sufficient stability for the laterally disposed tube is achieved with inexpensive manufacturability.

According to an advantageous embodiment, the tube extending into the muffler interior may be mounted such that it is supported on the muffler insert under axial prestressing via the cone engaging in the mating cone. The bias eliminates any play between cone and countercone, which also relative movements between the pipe and muffler insert can be avoided. The support effect for the respective pipe is thereby improved.

According to a special embodiment, the axial preload, with which the pipe is supported on the muffler insert, can be selectively selected so that an axial minimum preload is maintained over the entire expected thermal operating range of the muffler. As a result, in particular thermal expansion effects can be taken into account, so that a sufficient stability for the silencer can be ensured under all operating conditions.

The cone can be designed cone segment-shaped or spherical segment-shaped at least on its outer contour. Fits to the counter-cone at least on its inner contour cone segment-shaped or spherical segment-shaped or funnel-shaped. If the cone has a spherical segment-shaped outer contour, in particular positional tolerances that can occur in the context of manufacturing, easily compensate, since the tube then does not have to be mounted exactly coaxial with the counter-cone of the muffler insert to achieve the desired support effect.

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 below can be used not only in the particular combination given, but also 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

einen stark vereinfachten Längsschnitt durch einen Schalldämpfer,

Fig. 2

einen Querschnitt des Schalldämpfers entsprechend Schnittlinien II aus Fig. 1,

Fig. 3 bis 6

Längsschnitte des Schalldämpfers im Bereich eines seitlich angeordneten Rohres, bei verschiedenen Ausführungsformen.

Show, in each case schematically,

Fig. 1

a greatly simplified longitudinal section through a silencer,

Fig. 2

a cross-section of the muffler according to section lines II Fig. 1 .

Fig. 3 to 6

Longitudinal sections of the muffler in the region of a laterally disposed tube, in various embodiments.

According to the FIGS. 1 and 2 For example, a muffler 1 comprises two end faces 2 facing away from one another, a jacket 3 which is closed in the circumferential direction, at least one muffler insert 4, at least one inlet pipe 5 and at least one outlet pipe 6.

The muffler 1 is provided for installation in an exhaust system, not shown, of an internal combustion engine and can be used in particular in a motor vehicle. Preferably, the silencer 1 is a rear silencer, ie the silencer, which is within the exhaust system with respect. The exhaust flow direction de r last muffler flowed before the exhaust gas reaches the tailpipe of the exhaust system, which has the mouth of the exhaust system to the environment. The muffler is particularly advantageously a muffler arranged transversely in the mounted state. In the transverse muffler 1, an axial direction 7 of the muffler 1 extends substantially parallel to a horizontal transverse direction of the vehicle. In order to be able to install the silencer 1 more easily transversely in the vehicle, at least one of the tubes, that is to say at least one inlet tube 5 and / or one outlet tube 6, extends through the jacket 3 into the silencer interior 8. In the example shown, exactly one pipe, namely the inlet pipe 5, extends through the casing 3. Preferably, only a single inlet pipe 5 is provided. In contrast, more than one outlet pipe 6 may be provided. Although in the following description only the inlet tube 5 is the laterally penetrating tube 5, 6, in another embodiment with opposite flow direction, the outlet tube 6 may be the tube 5, 6 penetrating laterally of the jacket 3. Likewise, an embodiment is possible in which both at least one inlet pipe 5 and at least one outlet pipe 6 are arranged laterally and penetrate the jacket 3. Optionally, all the inlet and outlet pipes 5, 6 can be connected laterally to the casing 3.

The inlet pipe 5 is fixed to the jacket 3. In the example, at least one welded joint 9 is provided with which the inlet pipe 5 is fastened to the casing 3. This may be e.g. to act around a circular closed circumferential weld, creating a gas-tight connection is created at the same time. Alternatively, it is also possible e.g. in the manufacture of the muffler 1, the inlet pipe 5 to be fixed by means of at least one welding point or a staple on the jacket 3. When installing the muffler 1 in an exhaust system then a corresponding feed pipe can be connected to the inlet pipe 5. When attaching the feed tube then a circumferential weld can be generated. Preference is then given to the attachment of a three-cut seam, which simultaneously three sheets, so here the inlet pipe 5, the jacket 3 and the feed tube connects to each other.

For this purpose, the inlet pipe 5 passes through an opening 17 incorporated laterally into the casing 3. The respective welded connection 9 can be formed at an end face of an outwardly projecting collar 18 which surrounds the opening 17.

At its inner end, the inlet tube 5 has a cone 10, which engages in a matching or complementarily shaped counter-cone 11, which is provided on the muffler insert 4. Due to this positive engagement of the cone 10 in the suitably shaped counter-cone 11 results for the inlet tube 5 with respect to its pipe longitudinal axis 12 a radial and axial support on the muffler insert 4. Thus, the inlet tube 5 on the one hand on the jacket 3 and on the other hand spaced on the in the countercone 11 engaging cone 10 supported on the muffler insert 4. As a result, the inlet tube 5 can absorb moments and support the forces occurring during operation without further notice.

It is particularly advantageous if the inlet pipe 5 is mounted in such a way that it is supported on the muffler insert 4 under an axial pretensioning with respect to the pipe longitudinal axis 12. This axial preload is in Fig. 1 indicated by a double arrow and denoted by 13. The axial prestress 13 acts between the muffler insert 4 and the jacket 3 and is transmitted via the inlet pipe 5 between the jacket 3 and the muffler insert 4. In other words, the inlet tube 5 engages with its cone 10 under the axial bias 13 in the counter-cone 11 a.

Preferred is an embodiment in which the axial preload 13 is not chosen arbitrarily, but has a predetermined value. In particular, the axial preload 13 can be deliberately set so large that an axial minimum preload is ensured for the entire temperature range to be expected during operation of the muffler. The thermal operating range can range in a vehicle application, for example. From -40 ° C to + 500 ° C, if it is a rear silencer.

The cone 10 is expediently integrally formed on the inlet tube 5. For example. The inner end of the inlet tube 5 is converted to produce the cone 10. Basically, however, a built variant is possible.

The counter-cone 11 is formed on a console 14 of the muffler insert 4. This console 14 is attached here to two shelves 15 of the muffler insert 4, which are each arranged between the two end shelves 2.

Suitably, the counter-cone 11 is integrally formed on the console 14. For example, the console 14 is a sheet metal part which is made from a flat sheet metal blank by forming. Likewise, a built version is possible. Suitably, the console 14 is configured so that it is resilient in the region of the mating cone 11 in the tube longitudinal axis 12 resiliently. This resilient compliance facilitates the generation of the axial preload 13. During mounting, the bracket 14 is tensioned like a spring to produce the preload 13. In order to produce a comparatively high bias voltage 13, the console 14 is designed with a comparatively high spring stiffness. This can be realized, for example, in that the console 14 is designed as a floor, as in the example shown, which extends transversely to the tube longitudinal axis 12.

The jacket 3 is formed by winding a sheet metal part. Accordingly, this is a manufactured in the winding construction muffler 1. Eg. can the jacket 3 according to Fig. 2 have a longitudinal fold 16 which extends parallel to the longitudinal axis of the muffler 7. Suitably, the longitudinal fold 16 is positioned on a side facing away from the inlet pipe 5 side.

At least one of the end floors 2, here in Fig. 1 right end bottom 2, may be part of the muffler insert 4. According to the winding construction of the muffler 1, the muffler insert 4 is axially, that is used parallel to the muffler longitudinal axis 7 and thus the front side in the shell 3. It may be expediently provided to match the outer dimension of the insert 4 and the inner dimension of the shell 3 so that the muffler insert 4 relative to the longitudinal axis of the muffler 7 rests or is held under radial bias on the casing 3.

The at least one outlet pipe 6 extends through one of the end floors 2, here by the in Fig. 1 Right end 2 shown on the right, which belongs to the silencer insert 4 in the example. In addition, the outlet pipe 6 extends in the example by one of the shelves 15, which are provided for positioning the console 14, and by a further intermediate bottom 19, which is arranged between the aforementioned intermediate bottom 15 and the corresponding end floor 2. The outlet pipe 6 is fastened at least to the end floor 2, for example by means of a welded connection 20, in order to realize a gas-tight connection here as well. The end floors 2 are attached axially to the jacket 3 and inserted therein and fixedly connected to the jacket 2, z. B. with a circumferential fold joint 21st

According to the FIGS. 1 and 2 can the cone 10 in the circumferential direction of the inlet tube 5 annularly supported on the counter-cone 11 is supported. As a result, in each direction, a radial support of the inlet tube 5 on the muffler insert 4 is possible.

Like that FIGS. 1 and 2 can be seen, cone 10 and counter-cone 11 are spaced from the jacket 3. This is achieved by a distance from the shell 3 in the tube longitudinal axis 12 positioning the console 14 relative to the shell 3. Transverse to the pipe axis 12, the console 14 according to Fig. 2 be supported on the jacket 3. In particular, the console 14 is arranged approximately centrally in the silencer interior 8, in relation to the tube longitudinal axis 12.

The inlet pipe 5 is axially open, so that the exhaust gas can flow through the cone 10 and through the counter-cone 11, ie through the console 14. Accordingly, the inlet pipe 5 is fluidly connected to the muffler interior 8 by the cone 10 engaging in the mating cone 11. For example the inlet pipe 5 opens through the console 14 into a space 22 which is formed in the silencer interior 8 by the silencer insert 4. Said space 22 is laterally bounded by the intermediate walls 15, the console 14 and by a portion of the shell 3. The side walls 14 and / or the console 14 may be configured to be gas-permeable or sound-permeable, for example by means of openings or by means of a perforation. The outlet pipe 6 begins in the example shown in said space 22 and leads out of the muffler 1. The outlet tube 6 may have a perforation 23 to communicate with a space 24 formed between the partitions 15, 19. Also, the intermediate wall 19 may be designed to be permeable to gas or sound permeable to increase the volume of the space 24 to the end floor 2, so that, for example, a space 25 which is formed between the intermediate bottom 19 and the end bottom 2, can be used as adsorption ,

The muffler insert 4 shown here is also equipped with support elements 26, which support the individual floors 15,19,2 of the muffler insert 4 in the axial direction 7 to each other. As a result, the axial insertion of the muffler insert 4 is facilitated under radial bias in the shell 3, since tilting of the plates 15,19,2 is hindered.

According to the FIGS. 3 to 6 For the cone 10 and the counter cone 11 different configurations or embodiments can be realized. For example. can the cone 10 according to Fig. 3 have a cone-segment-shaped outer contour 27. According to the FIGS. 4 to 6 can the outer contour 27 of the cone 10 also be designed spherical segment. Likewise, other shapes for the outer contour 27 are conceivable.

According to Fig. 3 can the counter-cone 11 have a conical-segment-shaped inner contour 28. At coordinated angles and coaxial alignment of cone 10 and counter-cone 11, this results in a particularly intensive planar and annularly closed support of the inlet tube 5 on the console 14.

However, the counter-cone 11 can also be a spherical segment-shaped inner contour 28 according to Fig. 5 or a funnel-shaped inner contour 28 according to Fig. 6 exhibit. The funnel-shaped inner contour 28 according to Fig. 6 Characterized in relation to the spherical segment-shaped inner contour 28 Fig. 5 and with respect to the cone-segment-shaped inner contour 28 of the FIGS. 3 and 4 in that the inner contour 28 has a curved profile which is convex toward the cone 10.

In the embodiments of the FIGS. 4 to 6 meets a cone 10 with spherical segment-shaped outer contour 27 on a cone-segment-shaped inner contour 28 (FIG. Fig. 4 ) or on a spherical segment-shaped inner contour 28 (FIG. Fig. 5 ) or on a funnel-shaped inner contour 28 (FIG. Fig. 6 ) of the counter-cone 11. In these embodiments, it also comes to a circumferentially closed linear contact between cone 10 and counter-cone 11, if no exact coaxial alignment between the cone 10 and counter-cone 11 is present. These embodiments thus make it possible to compensate for manufacturing tolerances. Preferred is the embodiment according to Fig. 4 , in which a spherical segment-shaped outer contour of the cone 10 cooperates with a conical-segment-shaped inner contour 28 of the mating cone 11. This embodiment can be realized comparatively inexpensively.

The silencer 1 presented here can preferably be produced as follows: First, the respective muffler insert 4 is inserted into the shell 3 on the face side, ie parallel to the muffler longitudinal axis 7. Subsequently, the inlet tube 5 is inserted laterally into the opening 17 of the shell 3, and indeed until the cone 10 engages in the counter-cone 11. Subsequently, the inlet pipe 5 is fixed to the jacket 3.

Preferably, the inlet tube 5 is inserted as far as through the opening 17 in the muffler interior 8 before attaching the inlet tube 5 to the shell 3 until the inlet tube 5 via the engaging in the mating cone 11 cone 10 with the axial bias 13, in particular with the predetermined axial Preload 13, is supported on the muffler insert 4. The attachment of the inlet pipe 5 on the jacket 3, ie in particular the attachment of the welded joint 9, then takes place with maintained axial prestress 13, that is, while the inlet pipe 5 is axially prestressed supported on the muffler insert 4. As a result, the previously, in particular targeted, applied bias 13 can be preserved.

Claims (10)

1. A silencer for an exhaust system of an internal combustion engine, in particular of a motor vehicle,

   - having two face end bottoms (2) facing away from each other,

   - with a closed circumferential jacket (3) in circumferential direction,

   - with at least one silencer insert (4),

   - with at least one inlet pipe (5),

   - with at least one outlet pipe (6),

   - wherein at least one of the pipes (5, 6) extends through the jacket (3) into the silencer interior (8) and is fastened to the jacket (3),
   characterized in that

   - the pipe (5, 6) extending through the jacket (3) as a cone (10) on its end located inside,

   - the silencer insert (4) comprises a counter-cone (11),

   - the cone (10) engages in the counter-cone (11).
2. The silencer according to Claim 1,
   characterized in that
   the pipe (5, 6) extending through the jacket (3) is so attached that it is supported on the silencer insert (4) under axial preload (13) via the cone (10) engaging in the counter-cone (11).
3. The silencer according to Claim 2,
   characterized in that
   the respective pipe (5, 6) supports itself on the silencer insert (4) under a predetermined axial preload (13), which can be selected in particular so that over the entire thermal operating range of the silencer (1) to be expected, an axial minimum preload is retained.
4. The silencer according to any one of the Claims 1 to 3,
   characterized in that

   - the cone (10) comprises a segment of a cone shaped or segment of a cone shaped outer contour (27), and/or

   - the counter-cone (11) has a segment of a cone shaped or segment of a sphere shaped or funnel shaped inner contour (28), and/or

   - the counter-cone (11) is formed complementarily to the cone (10).
5. The silencer according to any one of the Claims 1 to 4,
   characterized in that

   - the cone (10) is integrally formed on the respective pipe (5, 6), and/or

   - the counter-cone (11) is formed on a bracket (14), which is fastened to two intermediate bottoms (15) arranged between the end bottoms (2), wherein it can be provided in particular that the counter-cone (11) is integrally formed on the bracket (14).
6. The silencer according to Claim 5,
   characterized in that

   - the bracket (14) is configured and/or attached so that it is spring-elastically yielding in the region of the counter-cone (11) parallel to the longitudinal axis (12) of the pipe (5, 6) comprising the cone (10), and/or

   - the bracket (14) is configured as a bottom extending transversely to the longitudinal axis (12) of the pipe (5, 6) comprising the cone (10).
7. The silencer according to any one of the Claims 1 to 6,
   characterized in that

   - the jacket (3) is formed by wrapping a sheet metal part, and/or

   - the jacket (3) comprises a longitudinal fold (16), which is located in particular on a side facing away from the pipe (5, 6) penetrating the jacket (3), and/or

   - at least one of the end bottoms (2) forms a constituent part of the silencer insert (4), and/or

   - the silencer insert (4) is inserted in the jacket (3) at the face end, and/or

   - the jacket (3) bears against the silencer insert (4) in a preloaded manner, and/or

   - at least one other one of the pipes (5, 6) extends through one of the end bottoms (2) and is fastened to the end bottom (2).
8. The silencer according to any one of the Claims 1 to 7,
   characterized in that

   - the cone (10) supports itself in circumferential direction of the respective pipe (5, 6) annularly closed on the counter-cone (11), and/or

   - the cone (10) and counter-cone (11) are spaced from the jacket (3), and/or

   - the respective pipe (5, 6) through the cone (10) and through the counter-cone (11) is fluidically connected to the silencer interior (8), in particular to a space (22) formed by the silencer insert (4) in the silencer interior (8).
9. A method for producing a silencer (1) for an exhaust system of an internal combustion engine, in particular of a motor vehicle,

   - with which at least one silencer insert (4) is pushed at the face end into a closed circumferential jacket (3) in circumferential direction,

   - with which at least one pipe (5, 6) is inserted into an opening (17) of the jacket (3) so far until a cone (10) on the preceding end of the pipe (5, 6) engages in a counter-cone (11) formed on the silencer insert (4),

   - with which the respective pipe (5, 6) is fastened to the jacket (3).
10. The method according to Claim 9,
    characterized in that

    - the respective pipe (5, 6) is inserted so far that the pipe (5, 6) via the cone (10) engaging in the counter-cone (11) is supported on the silencer insert (4) with axial preload (13),

    - the respective pipe (5, 6) is fastened to the jacket (3), while it is supported on the silencer insert (4) in an axially preloaded manner.

Images