EP3173595B1 - Silencer - Google Patents

Description

The present invention relates to a muffler for an exhaust system of an internal combustion engine.

Mufflers with housing usually have a peripheral circumferential shell and two axial ends (eg JPS54143941U . EP2520775 A1 . WO2013125764 A1 ) In the housing can be arranged axially between the ends at least one intermediate bottom. Such shelves serve on the one hand to auszusteifen the case. On the other hand, such shelves can also be used to position or hold tubes within the housing. In principle, a welded connection can be used to fasten such a pipe to an intermediate floor. However, it has been found that welds in the, usually ferritic, alloys used to make the tubes and shelves in silencers increase the risk of intergranular corrosion. It is therefore increasingly transferred to fasten such pipes by means of positive and / or non-positive connections on the respective intermediate floor. Such form and / or frictional connections come without material connection, whereby the risk of intergranular corrosion is significantly reduced. Such positive and / or frictional connections are, for example, compounds which are associated with a plastic deformation on the tube and / or on the intermediate bottom in order to bring about the desired fixation. Particularly advantageous in this case, a rib fixation has been found. For this purpose, the intermediate bottom in the region of an opening, in which the respective tube is to be inserted, equipped with a ring collar. Then the pipe is inserted into the opening, so that the ring collar runs around the outside of the pipe. Then be on the pipe by plastisehe Forming two ribs formed axially projecting from both sides of the annular collar radially outward from the remaining outer contour of the tube. As a result, the annular collar and thus the intermediate floor is axially fixed between these two ribs by positive locking. The respective rib can be configured as an annular rib which extends annularly in the circumferential direction or can be formed by a plurality of rib segments distributed in the circumferential direction. For such a rib fixation only tubes with a comparatively large diameter currently come into consideration.

In mufflers Helmholtz resonators are often used, which have a resonator and a resonator tube, which is often referred to as a neck. Such a Helmholtz resonator is not flowed through by the exhaust gas, but only fluidly or acoustically coupled to the exhaust gas flow. The resonant frequency of such a Helmholtz resonator is determined by the volume enclosed by the resonator chamber and by the dimensions of the resonator tube. The dimensions of the resonator tube are determined at least by the diameter of the resonator tube and by the length of the resonator tube. In this case, for the resonant frequency of the Helmholtz resonator with respect to the dimensions of the Resonatorrohrs on the one hand, a proportional relationship with the pipe diameter, while on the other hand with the pipe length is a reciprocal proportional relationship. This means that the resonance frequency can be increased on the one hand by increasing the pipe diameter and on the other hand by reducing the pipe length.

In order to fix such a resonator tube by means of a rib fixation on at least one intermediate floor, the resonator tube must be provided with a relatively large diameter. Due to the relationship described above between the resonance frequency and the Dimensions of the resonator tube, an increase in the tube diameter also requires an increase in the tube length, if the resonance frequency is to remain constant. By specifying a comparatively large diameter for the resonator tube, problems may therefore arise in silencers which have a relatively small, predetermined installation space. In particular, the required length for the resonator tube may be greater than the installation space available in the muffler for this purpose.

The present invention is concerned with the problem of providing an improved embodiment for a silencer of the type described above, which is particularly characterized in that on the one hand a Helmholtz resonator can be realized, while on the other hand, the resonator tube by means of a positive and / or non-positive connection at a the resonator space limiting intermediate floor can be attached.

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

The invention is based on the general idea of extending the resonator tube within the resonator cavity by means of a tube-in-tube arrangement. For this purpose, an end section of the resonator tube is inserted into an overtube inside the resonator chamber. The overtube is closed at the end, which faces away from the intermediate bottom, which is penetrated by the resonator tube. The overtube has an internal cross-section which is larger than an external cross-section which the resonator tube has in its end section. As a result, an additional space is formed radially between the overtube and the resonator, through which the fluidic and acoustic coupling between the resonator tube and resonator takes place. In that regard, the length of the overtube to the length of the resonator tube are added. Likewise, the volume of the additional space can be added to the volume enclosed by the resonator tube. As a result, even with a relatively large cross section of the resonator tube, a sufficient length for the resonator tube can be realized in order to realize a Helmholtz resonator with the respective desired resonant frequency in the silencer. As a result, the form and / or frictional connection for axially fixing the resonator tube to the intermediate floor can be realized.

Advantageously, an embodiment in which the overtube is axially secured by means of a spaced axially from the intermediate bottom separate form and / or frictional connection on the resonator tube. In particular, it can be provided that the overtube is fastened exclusively to the resonator tube, so that it is radially and axially spaced in the resonator chamber from the rest of the housing.

Alternatively, it is also possible to fix the overtube to the housing so that it has no connection to the resonator tube. In particular, then the resonator tube ends free-standing within the overtube. In this case, the overtube in the resonator can also end free-standing.

In another alternative it can be provided that the overtube to the resonator tube is arranged contactless and radially spaced at the intermediate bottom is supported. This can lead to a simplified production.

The respective positive and / or non-positive connection can be produced by means of a plastic deformation of the resonator tube and / or the intermediate bottom in the region of the connection.

In another, particularly advantageous embodiment, the overtube can protrude into the intermediate bottom and be attached axially thereto by means of the positive and / or non-positive connection on the resonator tube. As a result, more axial length is available for the overtube. In addition, the production is simplified.

Suitably, the respective positive and / or non-positive connection may have an annular collar formed on the intermediate base or on the overtube, which surrounds the resonator tube in the circumferential direction. Likewise, the respective positive and / or non-positive connection may have two ribs formed on the resonator tube, which are arranged axially on both sides of the respective annular collar for the axial attachment of the annular collar on the resonator tube. Suitably, an outer cross section of the ribs is greater than an inner cross section of the respective annular collar. Thus, the respective annular collar is axially fixed by the two ribs by positive engagement on the resonator tube. Such a form and / or frictional connection can also be referred to as rib fixation. The ribs can be produced by plastic deformation of the resonator tube, e.g. by means of a hydraulic hydroforming process. Optionally, the region of the resonator tube lying axially between the ribs can also be radially plastically expanded, ie calibrated, in order to press it with the annular collar. Machines for producing such rib fixations are e.g. offered by Upland Technologies Inc. of Cambridge, Ontario, Canada under the name "Ridge Lock Machine".

Within such a rib fixation, the respective annular collar can abut axially between the ribs radially on the outside of the resonator tube. If a common rib fixation is provided for the intermediate bottom and the overtube on the resonator tube, only one ring collar is suitably supported Radially on the outside of the resonator tube, while at this ring collar then the other ring collar is supported radially on the outside.

Preferred is an embodiment in which the annular collar of the overtube is arranged radially between the resonator tube and the annular collar of the intermediate bottom.

If the overtube is arranged without contact with the resonator, it may be provided in another embodiment, that the annular collar of the intermediate bottom forms an inner U-leg of the resonator tube in the circumferential direction enclosing U-shaped edge portion of the intermediate bottom, said overtube radially on an outer U -Skel of this edge region is supported on a side facing away from the resonator tube side. A U-base, which connects the two U-legs together, is then facing the additional space and limits this axially. This results in a particularly easy to implement embodiment.

In another advantageous embodiment, the over-tube can be axially closed at its end remote from the intermediate tube penetrated by the resonator tube end by the housing or its shell or by another intermediate bottom, which limits the resonator axially. In this case, a communicating connection between resonator tube and additional space can be realized particularly simply by arranging the resonator tube with an open end axially spaced from this closed end of the overtube.

Alternatively, the over-tube may be axially closed off at its end facing away from the latter, which is penetrated by the resonator tube, by means of a separate cover which is fastened to the overtube. In this case, the resonator tube carries the overtube, while the overtube is spaced with the lid to the housing, so has no contact. As a result, thermally induced stresses can be avoided, which can occur when the overtube is supported on the one hand on the housing and on the other hand on the resonator tube.

In an advantageous embodiment, the intermediate space can be fluidically connected to the resonator tube via a proximal connection, which is located in the region of one end of the resonator tube, and via a distal, axially spaced distal connection located at the over tube in an area remote from the end of the resonator tube , be fluidly connected to the resonator. The axial distance between the proximal connection and the distal connection corresponds to the extension of the resonator tube, which is achieved by means of the overtube. Suitably, the additional space has no further fluidic connection to the resonator tube and to the resonator chamber, so that only the proximal connection and the distal connection are provided. The acoustic coupling between the resonator tube and the resonator cavity thus takes place through the proximal connection, through the intermediate space and through the distal connection.

According to an advantageous development, the proximal connection can be formed by a gap between the closed end of the overtube and the open end of the resonator tube. Alternatively, the proximal connection can be formed by a perforation formed on the tube, wherein the end of the resonator tube is closed. In particular, a common cover may be provided for closing the end of the resonator tube and the end of the overtube, which is fastened to the resonator tube and / or to the overtube. Such a lid may for example be pressed or jammed or crimped with the respective tube.

In another development, the distal connection may be formed by a perforation formed on the over tube.

The respective perforation may have a plurality of openings distributed in the circumferential direction.

For the housing of the muffler come basically any designs into consideration, e.g. Half-shell construction, wound construction, tube or barrel construction. In a preferred embodiment it can therefore be provided that the shell of the housing is formed by a jacket extending in the circumferential direction, wherein the axial ends of the housing are each formed by a separate end bottom with respect to the shell. The intermediate floor is then arranged axially between these end floors and spaced therefrom. Alternatively, an embodiment is also conceivable in which the sheath is formed by two half-shells, which also form the axial ends of the housing.

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 are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

Fig. 1

eine stark vereinfachte Prinzipdarstellung eines Schalldämpfers im Längsschnitt,

Fig. 2

eine stark vereinfachte Schnittansicht im Bereich eines Helmholtz-Resonators,

Fig. 3 bis 5

jeweils eine vergrößerte Schnittansicht des Helmholtz-Resonators im Bereich eines Überrohrs bei verschiedenen Ausführungsformen,

Fig. 6

eine Schnittansicht wie in Fig. 2, jedoch bei einer weiteren Ausführungsform.

Show, in each case schematically,

Fig. 1

a simplified schematic diagram of a silencer in longitudinal section,

Fig. 2

a greatly simplified sectional view in the region of a Helmholtz resonator,

Fig. 3 to 5

each an enlarged sectional view of the Helmholtz resonator in the region of an overtube in various embodiments,

Fig. 6

a sectional view as in Fig. 2 but in another embodiment.

Corresponding Fig. 1 includes a muffler 1, which is suitable for use in an exhaust system of an internal combustion engine, preferably a road vehicle, a housing 2, whose longitudinal central axis 3 defines an axial direction 4, which is indicated in the figures by a double arrow. The housing 2 can have any square and non-angular cross-section, such as a rectangular, square, circular or elliptical or oval cross-section. The housing 2 has a circumferentially encircling shell 5 and two axial ends 6. The housing 2 may be made for example in winding construction or in barrel or tube construction. Then according to the in Fig. 1 Shown example, the sheath 5 formed by a closed in the circumferential direction circumferential jacket 43. At the axial ends 6 are then end floors 44, the housing 2 at the two axial Close ends 6. It is clear that the housing 2 can in principle also be produced in half-shell construction. Then at least the two end floors 44 are missing.

The muffler 1 may have within the housing 2 at least one intermediate bottom 7, 8, 9, 10, which is arranged axially between the two ends 6 and between the end plates 44 and enclosed by the shell 5 and the jacket 43. In the example shown the Fig. 1 four intermediate floors 7, 8, 9, 10 are provided, of which in principle only the intermediate bottom 7 provided with the reference numeral 7 is required, while the other intermediate floors 8, 9, 10 can basically be dispensed with. Subsequently, these intermediate floors for better distinction as the first, second, third and fourth intermediate bottom 7, 8, 9, 10 according to their sequence in Fig. 1 be designated from right to left.

The muffler 1 contains a Helmholtz resonator 11, which is not traversed by the exhaust gas during operation of the muffler 1. The Helmholtz resonator 11 has a resonator chamber 12 and a resonator tube 13. Via the resonator tube 13, a region 14 through which exhaust gas flows during operation of the muffler 1 is acoustically and fluidically coupled to the resonator chamber 12. The resonator chamber 12 is bounded radially by the shell 5 or by the jacket 43 and axially on the one hand by said first intermediate bottom 7. Axial on the other hand, the resonator 12 is limited for example by the housing 2, in the example shown by one of the end plates 44. The resonator tube 13 penetrates the first intermediate bottom 7 and is axially fixed thereto by means of a positive and / or frictional connection 15, which will be described below with reference to FIGS Fig. 2 to 6 will be explained in more detail.

In the example of Fig. 1 Closes axially to the resonator 12 an expansion chamber 16 or an absorption chamber 16 at. The absorption chamber 16 differs from the expansion chamber 16 in that the absorption chamber 16 is filled with a sound-absorbing material. The expansion chamber 16 or absorption chamber 16 is axially bounded by the first and second intermediate bottom 7, 8 and radially through the shell 5 and the shell 43 and completely penetrated by the resonator tube 13. Accordingly, the resonator tube 13 also penetrates the second intermediate bottom 8, whereby the second intermediate bottom 8 on the resonator tube 13 can likewise be fastened by a positive and / or frictional connection 15.

In the housing 2, an inlet chamber 17 is further formed, into which an inlet pipe 42 opens, which passes through the jacket 43 for this purpose. A connecting tube 18 connects the inlet chamber 17 with a deflection chamber 19. The deflection chamber 19 is bounded radially by the jacket 43 and axially by the other end floor 44 and by the fourth intermediate floor 10. The fourth intermediate bottom 10 is here equipped with a perforation 20, whereby the deflection chamber 19 is fluidically connected to an outlet chamber 21, from which an outlet pipe 22 leads out. The outlet tube 22 passes through the fourth intermediate bottom 10 and the other end bottom 44. In this case, the outlet tube 22 may be fixed to the end bottom 44 and the intermediate bottom 10 each with a positive and / or frictional connection 15.

The outlet chamber 21 is bounded radially by the casing 43 and axially by the third intermediate bottom 9 and by the fourth intermediate bottom 10. The connecting tube 18 passes through the third intermediate bottom 9 and the fourth intermediate bottom 10 and can be attached thereto by means of a positive and / or non-positive connection 15. For the connection of the inlet pipe 42 with the jacket 43 and for the connection of the outlet tube 22 to the respective end floor 44 may be a welded joint preferred to achieve the required tightness.

During operation of the exhaust system results in a Fig. 1 The flow-through region 14 thus comprises the inlet tube 42, the inlet chamber 17, the connecting tube 18, the deflection chamber 19, the outlet chamber 21 and the outlet tube 22. The resonator tube 13 is fluidly connected to the inlet chamber 17 in that the resonator chamber 12 is acoustically connected to the exhaust-gas-conducting region 14 via the resonator tube 13. The expansion chamber 16 or the absorption chamber 16 may be acoustically connected to the exhaust-carrying region 14 by a perforation, either directly by a perforation formed in the second intermediate bottom 8 or indirectly by a perforation formed in the first intermediate bottom 7 or by a resonator tube 13 within the Expansion chamber 16 and the absorption chamber 16 formed perforation. Preferably, it is provided here that the resonator tube 13 is imperforated inside the expansion chamber 16 or absorption chamber 16 and that the first intermediate bottom 7, which axially limits the resonator chamber 12, is likewise imperforate.

According to the Fig. 1 to 6 the resonator tube 13 is provided in the resonator 12 with an over tube 24 into which an end portion 25 of the resonator tube 13 is inserted axially. As a result, the over-tube 24 envelops the end section 25. Furthermore, the over-tube 24 is closed at an end 26 facing away from the first intermediate bottom 7. An inner cross section of the overtube 24 and an outer cross section of the resonator tube 13 in the end portion 25 are matched to one another such that an additional space 27 is formed radially between the overtube 24 and the resonator tube 13. This additional space 27 is fluidically on the one hand with the resonator tube 13 and on the other hand with the resonator 12 acoustically in connection. As a result, the resonator tube 13 is fluidically and acoustically connected to the resonator chamber 12 through this intermediate space 27.

While at the in Fig. 1 indicated oversimplified embodiment, the overtube 24 in the resonator 12 ends free-standing, so that it has no connection to the resonator tube 13, the show Fig. 2 to 5 preferred embodiments in which the overtube 24 is attached to the resonator tube 13. In the example of Fig. 6 the overtube 24, however, is attached to the intermediate bottom 7. Preferably, for the axial attachment of the resonator tube 13 on the overtube 24 also a positive and / or frictional connection 15 is used. In the examples of FIGS. 2 and 3 is the form and / or frictional connection 15 for attaching the overtube 24 on the resonator tube 13 axially spaced and thus formed separately from the positive and / or frictional connection 15, with which the first intermediate bottom 7 is attached to the resonator tube 13. In Fig. 2 is also recognizable that the resonator tube 13 is axially fixedly connected via a further positive and / or frictional connection 15 with the second intermediate bottom 8.

In the embodiments of the 4 and 5 the overtube 24 extends axially into the first intermediate bottom 7. As a result, the overtube 24 can be fastened to the resonator tube 13 together with this first intermediate bottom 7 by means of a common positive and / or non-positive connection 15.

In the embodiments shown here, the respective form and / or frictional connection 15 is designed as a rib fixation. For this purpose, a respective annular collar 28, 29, 30 is formed on the respective intermediate bottom 7, 8 and on the over tube 24. The first intermediate bottom 7 shows the annular collar 28. At the overtube 24, the annular collar 29 is formed. At the second intermediate floor 8 is according to Fig. 2 the annular collar 30 is formed. The respective annular collar 28, 29, 30 surrounds the resonator tube 13 in its circumferential direction. Furthermore, the respective rib fixation, which is also referred to below as 15, on the resonator tube 13 comprises two radially outwardly projecting bead-like ribs 31 and 32 and 33, respectively. The ribs 31 are formed axially on both sides of the annular collar 28 of the first intermediate bottom 7. The ribs 32 are arranged axially on either side of the annular collar 29 of the overtube 24. The ribs 33 are arranged axially on either side of the annular collar 30 of the second intermediate bottom 8. In the example of Fig. 4 the annular collar 28 of the first intermediate bottom 7 and the annular collar 29 of the overtube 24 between the two ribs 31 are arranged. The ribs 31, 32, 33 are matched to the annular collar 28, 29, 30 so that an outer diameter of the respective annular rib 31 is greater than an inner diameter of the respectively associated, thus axially fixed annular collar 28, 29, 30th

In the preferred examples shown here, the ribs 31, 32, 33 are in each case designed as annular ribs which encircle in the circumferential direction of the resonator tube 13. Alternatively, these ribs 31, 32, 33 can also be realized by a plurality of rib segments distributed in the circumferential direction of the resonator tube 13.

The ribs 31, 32, 33 can be formed, for example, by means of a plastic forming process on the resonator tube 13, while the annular collar 28, 29, 30 are already pushed onto the resonator tube 13. In this case, at the same time a radial compression between the outside of the resonator tube 13 and an inner side of the respective annular collar 28, 29, 30 take place. The plastic deformation can be realized for example by means of a hydraulic hydroforming process. Likewise come mechanical forming processes such as, for example, the above-mentioned RidgeLock process of Upland Technologies Inc.

According to Fig. 4 it can be provided that the annular collar 29 of the overtube 24 is arranged radially between the resonator tube 13 and the annular collar 28 of the intermediate bottom 7. In principle, however, a reverse arrangement is conceivable. For this purpose, the annular collar 28 of the intermediate bottom 4 would have to be angled in the opposite direction.

In the examples of Fig. 1 and 2 the outer tube 24 is axially closed at its end 26 remote from the first intermediate bottom 7 by the end base 6. In contrast, the show Fig. 3 to 5 Embodiments in which the outer tube 24 is axially closed by a cover 34 at this 26 remote from the first intermediate bottom end 26. In these embodiments, it is further provided that with the help of the lid 34 at the same time also arranged in the overtube 24 end 35 of the resonator tube 13 is axially closed. In contrast, in the examples of the Fig. 1 and 2 said end 35 of the resonator tube 13 axially open.

The additional space 27 is fluidly connected on the one hand axially to the resonator tube 13 via a proximal connection 36, while on the other hand it is fluidically connected to the resonator chamber 12 via a distal connection 37. The proximal connection 36 is located in the region of the end 35 of the resonator tube 13, which is arranged within the overtube 24. On the other hand, the distal connection 37 is located on the over tube 24, in a region axially spaced from said end 35 of the resonator tube 13. Expediently, the over-tube 24, apart from the distal connection 37, has no further fluidic connection to the resonator chamber 12. The resonator tube too 13 has no further fluidic connection with the additional space 27 apart from the proximal connection 36.

In the examples of Fig. 1 . 2 and 6 For example, the proximal connection 36 is formed by an axial gap 38 formed axially between the closed end 26 of the overtube 24 and the open end of the resonator tube 35.

In the examples of Fig. 3 to 5 on the other hand, the proximal connection 36 is formed by a perforation 39 formed on the resonator tube 13. In these examples, the end 35 of the resonator tube 13 is axially closed.

In the example of Fig. 1 the distal connection 37 is formed by a radial gap 40. In contrast, among the Fig. 2 to 6 the distal connection 37 is formed in each case by a perforation 41 formed in the over-tube 24.

In the in the Fig. 1 and 6 In embodiments shown, the overtube 24 is arranged without contact with the resonator tube 13. While in the example of the Fig. 1 At its end facing the intermediate bottom 7 ends free-standing and thus axially spaced to the intermediate bottom 7, it is in the example of Fig. 6 supported on the intermediate bottom 7, and that radially spaced from the resonator tube 13. Further, in Fig. 6 provided that the intermediate bottom 7 has a U-shaped edge portion 46 which encloses a penetrated by the resonator tube 13 through opening 48 in the circumferential direction. As a result, the peripheral portion 46 also encloses the resonator tube 13 in the circumferential direction. The edge region 46 has in profile a radially inner inner U-leg 45, a radially outer outer U-leg 47 and a U-base 49, which connects the two U-legs 45, 47 with each other. The U-base 49 is facing the gap 27. As a result, the inner U-leg 45 forms the above-mentioned annular collar 28 of the intermediate bottom 7. The overtube 24 is axially mounted on the edge region 46 and radially supported on the outer U-leg 47. The edge region 46 axially opposite a recess 50 is formed at the end bottom 44, which forms an annular step 51. On this annular step 51, the overtube 24 is also axially mounted and radially supported thereon.

Claims (15)

1. A silencer for an exhaust system of an internal combustion engine,

   - with a housing (2) which has a casing (5) running in circumferential direction,

   - with a Helmholtz resonator (11), which is not flowed through by the exhaust gas and which has a resonator chamber (12) and a resonator pipe (13),

   - wherein the resonator chamber (12) is delimited radially by the casing (5) and axially by an intermediate base (7), which is arranged axially between two axial ends (6) of the housing (2),

   - wherein the resonator pipe (13) penetrates the intermediate base (7),
   characterized in

   - that the resonator pipe (13) is axially fastened to the intermediate base (7) by means of a form- and/or force-fitting connection (15),

   - that the resonator pipe (13) in the resonator chamber (12) is equipped with an overpipe (24), which encloses an end section (25) of the resonator pipe (13) and which is closed at an end (26) facing away from the intermediate base (7),

   - that the resonator pipe (13) is fluidically connected with the resonator chamber (12) through an intermediate space (27) formed radially between the overpipe (24) and the resonator pipe (13).
2. The silencer according to Claim 1,
   characterized in that
   the overpipe (24) is axially fastened to the resonator pipe (13) by means of a form- and/or force-fitting connection (15).
3. The silencer according to Claim 1 or 2,
   characterized in that
   the overpipe (24) projects up into the intermediate base (7) and together therewith is axially fastened to the resonator pipe (13) by means of the form- and/or force-fitting connection (15).
4. The silencer according to Claim 1,
   characterized in that
   the overpipe (24) is arranged in a contactless manner with respect to the resonator pipe (13) and, radially spaced apart with respect thereto, is supported on the intermediate base (7).
5. The silencer according to one of Claims 1 to 4,
   characterized in that
   the respective form- and/or force-fitting connection (15) has an annular collar (28, 29), formed on the intermediate base (7) and/or on the overpipe (24), which annular collar surrounds the resonator pipe (13) in circumferential direction, and two ribs (31, 32), formed on the resonator pipe (13), which, for the axial fastening of the annular collar (28, 29) to the resonator pipe (13), are arranged axially on both sides of the respective annular collar (28, 29) and the external diameter of which is greater than an internal diameter of the respective annular collar (28, 29).
6. The silencer according to Claims 3 and 5,
   characterized in that
   the annular collar (29) of the overpipe (24) is arranged radially between the resonator pipe (13) and the annular collar (28) of the intermediate base (7).
7. The silencer according to Claims 4 and 5,
   characterized in that

   - the annular collar (28) of the intermediate base (7) forms an inner U-leg (45) of a U-shaped edge region (46) of the intermediate base (7) surrounding the resonator pipe (13) in circumferential direction,

   - the overpipe (24) is supported radially on an outer U-leg (47) of this edge region (46).
8. The silencer according to one of Claims 1 to 7,
   characterized in that
   the overpipe (24) is axially closed at its end (26), facing away from the intermediate base (7), by the housing (2) or by a further intermediate base which axially delimits the resonator chamber (12).
9. The silencer according to one of Claims 1 to 8,
   characterized in that
   the overpipe (24) at its end (26) facing away from the intermediate base (7) is axially closed by a cover (34), which is fastened to the overpipe (24).
10. The silencer according to one of Claims 1 to 9,
    characterized in that
    the additional space (27) is fluidically connected with the resonator pipe (13) via a proximal connection (36) which is situated in the region of an end (35) of the resonator pipe (13), and is fluidically connected with the resonator chamber (12) via a distal connection (37), spaced apart axially therefrom, which is situated on the overpipe (24) in a region remote from the end (35) of the resonator pipe (13).
11. The silencer according to Claim 10,
    characterized in that
    the proximal connection (36) is formed by a gap (38) between the closed end (26) of the overpipe (24) and the open end (35) of the resonator pipe (13).
12. The silencer according to Claim 10,
    characterized in that
    the proximal connection (36) is formed by a perforation (39) formed on the resonator pipe (13), wherein the end (35) of the resonator pipe (13) is closed.
13. The silencer according to Claim 12,
    characterized in that
    a shared cover (34) for closing the end (35) of the resonator pipe (13) and of the end (26) of the overpipe (24) is provided, which is fastened to the resonator pipe (13) and/or to the overpipe (24).
14. The silencer according to one of Claims 10 to 13,
    characterized in that
    the distal connection (37) is formed by a perforation (41) formed in the overpipe (24).
15. The silencer according to one of Claims 1 to 14,
    characterized in that

    - the casing (5) of the housing (2) is formed by a jacket (43) running in the circumferential direction, wherein the axial ends (6) of the housing (2) are formed respectively by an end base (44) which is separate with respect to the jacket (43),

    - the casing (5) is formed by two half-shells, which also form the axial ends (6) of the housing (2).

Images