EP2757234B1 - Sound muffler and method for producing the same - Google Patents

Description

The invention relates to a silencer, in particular vehicle silencer, having an inner tube section and at least one resonator chamber formed outside the tube section, the tube section having in its jacket at least one opening which connects the interior of the tube section with the resonator chamber. The invention also relates to a vehicle with a silencer and a method for producing a silencer.

The JPS5087315U discloses a construction in the manner of a muffler with an inner pipe section surrounded by chambers. The inner pipe section has openings in its jacket, which connect the interior of the pipe section with the chambers. The inner tube section is composed of two adjacently arranged sheath segments.

The DE 10026355 A1 discloses a sound-absorbing air duct for an air intake tract of an internal combustion engine with an inner tube having radial openings, and an insulating sheath, which at least partially surrounds the inner tube radially outward. An outer tube completely encloses the inner tube and the insulating jacket. Both the outer tube and the inner tube each consist of two half-shells, wherein a half-shell of the inner tube is pivotally mounted on a half-shell of the outer tube and the other half-shell of the inner tube is pivotally mounted on the other half-shell of the outer tube. Inner tube, outer tube and insulation sheath are made of plastic. The disadvantage of this construction is that the production of such an air duct requires enormous effort. In particular, the mutual pivotal mounting of the individual half-shells requires several complex operations and can be realized in a reasonable cost only with plastic materials. This eliminates this solution in all applications where the use of metal, such as stainless steel, is required.

The WO 07101412 A1 discloses a silencer in modular design and its manufacture. For this purpose, a plurality of fluid guide elements is provided, which form a labyrinth of passages and resonator chambers. A continuous pipe is not provided, construction and construction are very complex and require a variety of items whose composition is extremely complex.

A silencer with an inner tube and outside arranged reflection chambers and channels is from the DE 3020492 C2 known.

The DE 736633 A discloses a muffler in which the inside pipe is not formed continuously. The medium passes through two chambers and annular spaces between two pipe sections. Radial openings connect the chambers to the annuli.

The last two documents have as inner tube sections a tube which is formed along its circumference in one piece. The disadvantage of such a construction is that commercially available tubes of a certain diameter have a minimum thickness of their shell. In order to achieve a lower shell thickness and thus a material and weight savings would require special constructions, which are very expensive and expensive. In addition, the introduction of radial openings in a finished tube is associated with considerable effort, since openings must be introduced mostly along the entire circumference of the tube, so that even the handling and orientation of the tube during processing requires considerable effort.

The aim of the present invention is to provide a silencer which does not have this disadvantage and which is simple and inexpensive to produce. With such a silencer, a material and weight saving should be possible. The assembly of the muffler and in particular the production of the inner pipe section with the openings in his coat should be uncomplicated and time-saving. Finally, the silencer should be characterized by an efficient sound insulation.

This object is achieved with a silencer mentioned above in that the shell of the inner pipe section from at least three, distributed along the pipe circumference (adjacently arranged) shell segments is composed, each extending in the axial direction from a first connector to a second connector, wherein first ends of the sheath segments are connected to the first connector and second, the first ends opposite ends of the sheath segments are connected to the second connector.

The production and assembly of at least three shell segments to an inner pipe section have proven to be particularly simple. The shell segments can be made individually and independently of each other and then assembled into an inner tube section. Since the segments are made individually, They can be cut out of a thin sheet and then bent into the right shape. The jacket of the inner pipe section can be designed with a smaller wall thickness, as is possible with pipes of the prior art. The resulting material savings makes the muffler lighter in weight and cost. The production of radial openings in the shell is facilitated by the fact that they are already introduced in the production of the individual shell segments. The assembly of the individual shell segments to the inner pipe section is not a difficulty.

The shell segments are prefabricated independently of other parts of the muffler, in particular independently of the resonator walls surrounding the resonator chamber (s) on the outside. This prefabrication of the sheath segments allows an optimization of the manufacturing process.

The shell segments each extend continuously from the first connector to the second connector, so that the inner tube section is continuous. The inner tube section serves to convey a medium, e.g. Compressed air of the turbocharger, (and is therefore a flow channel), while the resonator chambers (for example Helmholtz resonators) serve the reduction of sound by negative interference.

Each of the shell segments covers a circle segment in cross section normal to the axis of the pipe section. The required degree of bending of an initially flat piece of sheet metal in three or more shell segments remains relatively low and can be done with simple means, a bending tool, with high accuracy and reproducibility.

The shell segments are manufactured individually and reach only by their positioning and attachment to the fittings in a relatively fixed position. The shell segments are preferably connected to one another only via the connecting pieces, wherein in this embodiment a direct mechanical connection between the shell segments is not provided.

The term fitting is widely seen and may include pipes, fittings and pieces of hose. In the connecting piece, the medium conducted in the inner pipe section is conveyed further; the word part 'connection' refers to the fact that the sheath segments are connected to the connector. The connecting pieces are preferably in each case arranged predominantly or entirely outside the resonator chambers, one connecting piece forming the inlet and the other connecting piece forming the outlet of the silencer. Between the fittings, the shell segments are continuous, i. the inner tube section is not interrupted. For communication between the flow channel (inner pipe section) and the / the resonator (s) (n) provide the recesses in the shell segments.

Preferred is therefore an embodiment in which the shell of the inner tube section is composed of exactly three shell segments which extend along the circumference of the tube in each case by substantially 120 °, i. in the case of a circular pipe section, each shell segment covers one third of the circular shape. A bend of sheet metal pieces to this extent can be done without much effort and with high accuracy. In addition, it is preferred that all shell segments have the same shape, which further simplifies the manufacturing process.

As already mentioned, the jacket segments are preferably formed from individual, pre-bent sheet metal pieces, preferably stainless steel sheet pieces, whereby high quality silencers are formed.

Preferably, the first and / or the second ends of the shell segments are welded to the first and / or second connector, whereby a reliable and easy to make connection takes place.

Preferably, the first and / or the second ends of the shell segments are positively connected to the first and / or second connection piece. This can be done for example by means of clamping or pressing connections or clamps.

Preferably, the first and / or the second ends of the shell segments each have at least one flange-shaped portion. This flange-shaped portion is preferably on the front side of the connector and facilitates the positioning and attachment of the corresponding end of the connector.

Preferably, the first and / or the second ends of the shell segments each have at least one apron-shaped portion, wherein the skirt-shaped portion rests against a connecting piece. A skirt-shaped section also facilitates positioning and improves firm connection with the fitting. In conjunction with a flange-shaped section, the attachment can be made particularly simple

Preferably, at least one connecting piece is a pipe, a pipe piece, a hose or a hose piece, whereby the shell damper can be coupled with the connecting lines in the best possible way.

Preferably, the axially extending edges of adjacent shell segments are loosely adjacent to each other. It is therefore not necessary here to connect the shell segments along the axially extending edges. Since the resonator chamber walls seal the muffler and thus also the inner pipe section to the outside, a complete tightness of the inner tube and thus along the axially extending edges is not necessary, especially since openings are also provided in the direction of resonator. Preferably, the axially extending edges of all shell segments are loosely abutted, i. these edges are not directly connected. This does not exclude that they preferably touch along their entire length.

Another advantage of this embodiment results from the fact that the three sheath segments or shells can lie loosely along each other longitudinally, ie the axially extending longitudinal sides or edges of adjacent sheath segments need not be connected to one another. The loose abutment can be used for tolerance compensation for the fittings. If the connection diameters are not exactly correct, the gaps between the segments are simply varied for tolerance compensation. In a preferred embodiment, therefore, results in at least between two adjacent sheath segments extending in the axial direction gap. Of course, it is also conceivable that axially extending gaps are formed between all longitudinal sides.

A partition that separates two resonator chambers from each other, may be formed as an annular wall portion through which the inner pipe section passes. Preferably, this partition lies with its inner edge on the shell segments, whereby they are additionally held or supported. A firm connection between partition and shell segments is not absolutely necessary. Preferably, the partition is loosely against the shell segments; the latter are held by the fittings anyway. With its outer edge, the partition wall abuts against the outwardly sealing resonator chamber wall. This provides a mechanically stable construction.

Preferably, the cross section of the shroud segments is arcuate, preferably arcuate, normal to the axial direction, thereby resulting in a space-saving and optimized in terms of sound insulation geometry. The production of the inner tube section by the same shaped shell segments is possible.

Preferably, each shell segment at least one, preferably at least two recesses, which form the openings in the shell of the inner pipe section. The recesses may be in the individual shell segment all-round openings or be an open towards an axially extending edge of the shell segment recess, which are only after the assembly of the individual shell segments to an inner pipe section to all sides enclosed openings.

Preferably, the shell segments forming the inner pipe section have the same size and the same shape, wherein preferably the shape, arrangement and size of the recesses in all shell segments are the same. This results in a uniform shape for all shell segments, so that the manufacturing process is greatly simplified.

Preferably, the at least one resonator chamber surrounds the inner tube section along its entire circumference, thereby creating a space-saving and optimized in terms of sound insulation geometry.

Preferably, the muffler has at least two resonator chambers, which are arranged one behind the other in the axial direction, the mantle of the inner tube section being first Openings, which open into the first resonator and second openings, which open into the second resonator. This solution is particularly efficient in soundproofing.

Preferably, the inner tube section is completely surrounded by resonator chamber walls. Here, leakage is achieved to the outside through the resonator chamber walls, so that no perfect tightness of the inner pipe section is required.

Preferably, the muffler is a turbocharger muffler, which is arranged on the pressure side of a turbocharger. The turbocharger silencer serves to reduce noise emissions on the pressure side of the turbocharger. The muffler can be plugged onto a short pressure hose directly at the outlet of the turbocharger and e.g. be secured with a spring band clamp.

The above object is also achieved with a vehicle, in particular road-bound vehicle, having a muffler, in particular a turbocharger muffler, which is formed according to one of the embodiments described above.

The abovementioned object is also achieved with a method for producing a silencer, in particular a vehicle silencer, having an inner tube section and at least one resonator chamber formed outside the tube section, the tube section having in its jacket at least one opening which encloses the interior of the tube section with the resonator chamber connects, reaches. The individual shell segments are completely prefabricated and assembled the prefabricated shell segments during assembly of the muffler to the inner tube section

This is done by the shell segments are prefabricated as individual parts and that is formed by assembling the prefabricated shell segments of the shell of the inner tube section, wherein the shell segments are distributed along the pipe circumference and each extend in the axial direction from a first connector to a second connector and that first ends of the sheath segments are connected to the first connector and second ends of the sheath segments opposite the first ends are connected to the second connector.

The prefabricated shroud segments connected as loose individual parts (i.e., initially unrelated to each other or to other parts of the resulting muffler) are brought into a fixed position with each other only during assembly to the inner tube section.

As a result, the manufacturing process is divided into two steps. In a first step, the shell segments are individually prefabricated. In a second step, the prefabricated shell segments only need to be assembled. These. Allows manufacturing of shroud segments with high accuracy, during the assembly no difficulties, because tolerances in the shroud segments can be kept low. The shroud segments are attached with their ends to the respective fittings. Preferably, there is no direct bond between the adjacent shell segments via their axially extending edges. This reduces the mounting on the attachment to the opposing fittings.

The sheath of the inner tube section is composed of at least three sheath segments, preferably of exactly three sheath segments which extend along the circumference of the tube in each case by substantially 120 °. With three or more shell segments, the bending angle or segment angle is not too large to be produced reproducibly and with low tolerances. In the case of exactly three jacket segments, each of which covers a peripheral region of approximately 120 °, a manufacturing process (bending or segment angle is easily manageable, production of equally shaped shell segments as individual parts) as well as in terms of assembly (with three shell segments just a few parts to assemble) achieved optimized solution.

Preferably, the shell segments are each made by a bending operation of a piece of sheet metal, preferably a piece of stainless steel sheet, the shell segments are brought by the bending process in a form with arcuate, preferably circular cross-section. By this method very thin sheets can be used, for example, with a thickness of less than 1mm, which material, weight and cost savings can be achieved. The bending of the sheet metal piece in a mold to form a coat with one or more other shell segments, presents no problems Bending angle or segment angle is relatively small for three jacket pieces, preferably of the same size and shape, so that the observance of tolerance limits during the bending process causes no problems. An embodiment with exactly three shell segments, each covering an arc of 120 °, is also preferred here.

Preferably, the sheet metal pieces are cut before the bending process from a substantially flat sheet into the size of the shell segments. The shell segments are each made by cutting a piece of sheet metal from a substantially flat sheet and then bending the sheet piece into a shape in which it has an arcuate, preferably circular arc-shaped cross-section. Cutting from a flat sheet, e.g. by means of a laser, can be done with high accuracy.

In a preferred embodiment, the segments are made directly from a sheet metal strip. The sheet metal strip or strip is then prepared in the appropriate width, so that laterally no more processing is necessary and no waste / waste. In this embodiment, therefore, the width of the sheet metal strip already corresponds to the width of the jacket segment to be prefabricated. This allows a production 'on tape'.

Preferably, at least one flange-shaped portion is formed at each of the first ends and / or second ends of the shroud segments before the shroud segments are assembled to the inner tube portion, thereby facilitating subsequent positioning and attachment to the fitting.

At least one apron-shaped portion is preferably formed at the first ends and / or second ends of the shell segments before the shell segments are assembled to form the inner pipe section, thereby facilitating subsequent positioning and attachment to the fitting.

Preferably recesses are introduced into the piece of sheet metal prior to bending of the piece of sheet metal, which openings in the shell of the inner pipe section form in the assembled state of the shell segments, wherein preferably the introduction of the recesses is carried out by laser processing. In the un-bent state of the piece of sheet metal and the recesses can be very accurately introduced.

Preferably, the first ends and / or the second ends of the shell segments are welded to the first and / or second connector.

Preferably, the first ends and / or the second ends of the shell segments are positively connected to the first and / or second connection piece.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Fig. 1

einen erfindungsgemäßen Schalldämpfer;

Fig. 2

den inneren Rohrabschnitt einer Ausführungsform des erfindungsgemäßen Schalldämpfers;

Fig. 3

einen Fertigungsschritt eines Mantelsegmentes;

Fig. 4

einen weiteren Fertigungsschritt eines Mantelsegmentes;

Fig. 5

ein vorgefertigtes Mantelsegment;

Fig. 6

ein Fahrzeug mit einem Schalldämpfer, und

Fig. 7

Varianten eines mit dem erfindungsgemäßen Verfahren herstellbaren Schalldämpfers.

Each shows in a highly schematically simplified representation:

Fig. 1

a silencer according to the invention;

Fig. 2

the inner pipe section of an embodiment of the silencer according to the invention;

Fig. 3

a manufacturing step of a shell segment;

Fig. 4

a further manufacturing step of a shell segment;

Fig. 5

a prefabricated shell segment;

Fig. 6

a vehicle with a silencer, and

Fig. 7

Variants of a producible with the inventive method silencer.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or component names. Also, the location information selected in the description, such as above, below, laterally, etc. related to the immediately described and illustrated figure and are to be transferred to a new position in a change in position. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

The embodiments show possible embodiments of the muffler, which should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are mutually possible and this variation possibility due to the teaching of technical action by representational Invention in the skill of those skilled in this technical field. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiment variant, includes the scope of protection.

Fig. 1 shows a silencer 1 according to the invention with an inner tube section 2, which is surrounded by two, in the axial direction one behind the other arranged Resonatorkammern 14,15. In the jacket 3 of the inner pipe section 2 first openings 7 and second openings 8 are formed. The first openings 7 are spaced apart from the second openings 8 in the axial direction. The first openings 7 lead into the first resonator chamber 14 and the second openings 8 lead into the second resonator chamber 15. The resonator chambers 14, 15 surround the tube section 2 along its entire circumference in the form of an annular volume. The two resonator chambers 14, 15 are separated from each other by an annular partition wall. Resonator chamber walls 16 seal the silencer 1 to the outside. By an appropriate design of the resonator volumes and the openings 7, 8 corresponding to the frequencies to be damped, a negative interference can be achieved in which sound can be at least partially extinguished by appropriate phase shifts.

The annular partition wall between the resonator chambers 14, 15, through which the inner tube section 2 passes, lies with its inner edge on the shell segments 4, 5, 6, whereby the latter are additionally held or supported. The position of the partition wall in the housing part determines the volume of the resonator chambers. The partition can be as separate Part, for example, be used with a flared outer and / or inner edge at the desired location in the housing part formed by the resonator chamber wall 16 and connected thereto, for example, be welded. Of course, it is conceivable that the partition is also firmly connected to the shell segments 4, 5, 6, for example, welded.

The inner tube section 2 continues at its two ends in connecting pieces 11, 12. As already in Fig. 1 indicated is the jacket 3 composed of individual shell segments 4, 5, 6. Adjacent shell segments lie with their axially extending edges 13 to each other loosely.

Fig. 2 shows the inner pipe section 2 in detail. At the beginning, it should be noted that the connecting pieces 11, 12 compared to Fig. 2 have different shape. Basically, all possible forms are conceivable; the connecting pieces 11, 12 may be formed as a piece of pipe, as a pressure hose or hose piece.

According to the invention, the pipe section 2 consists of individual shell segments 4, 5, 6 which have recesses 17, 18. These form in the assembled state, the openings 7, 8 of the shell 3. In the illustrated preferred embodiment, the individual shell segments each extend over a third of the pipe circumference. They are the same in terms of shape, size and recesses.

At one of their ends, the second ends 10, the shell segments each have two flange-shaped sections 21 with axially projecting apron-shaped sections 22. Sections 21, 22 serve to position and secure the shell segments to the face of the second connector 12. The attachment may be e.g. done by welding or by a non-positive connection. At the first ends 9 of the shell segments no special shape is provided. The first ends 9 are e.g. inserted in an annular gap or recess of the first connector 11 and there, for example. secured by welding.

The advantage of the construction of the inner pipe section 2 is that the shell segments individually, ie independently of other parts of the resulting muffler, prefabricated and then assembled in the manner of a modular system to the pipe section 2 can be. The individual sheath segments are thus initially available as prefabricated items that are loose, that is connected to each other in any way. Only when assembling the inner pipe section, the shell segments are joined together and brought a fixed position to each other.

The Fig. 3 to 5 outline in steps a possible manufacturing process for a silencer. According to Fig. 3 be cut in a first step sheet metal pieces 19 in the size of the future shell segments from a flat sheet 20. Preferably, even in the flat state of the sheet metal pieces 19 and the recesses 17,18 are cut out. These steps are preferably carried out by laser cutting.

In Fig. 4 a sheet metal piece 19 is subjected to a bending process. In this case, by means of a bending tool, for example an arrangement of rollers or rollers positioned relative to one another, an arcuate, preferably arc-shaped contour of the sheet metal piece 19 is produced.

In Fig. 5 an already prefabricated shell segment 4 is shown, on which also the flange-shaped portions 21 and thereof axially projecting apron-shaped portions 22 are formed. These are formed integrally with the shell segment 4. Of course, it would be conceivable to provide only one (single) flange-shaped section 21, ie without a skirt-shaped section. The sections 21, 22 can be mitgeformt before and / or during the bending process.

After assembly of the inner pipe section 2, the attachment of the resonator chambers 14, 15 and the resonator chamber walls 16 together with their attachment to the muffler takes place.

Fig. 7 shows possible variants of a pipe section 2 of a muffler, which can be produced by a manufacturing method according to the invention. In the first variant, a composite of three shell segments 4, 5, 6 pipe section 2 can be seen; to the right of one of four shell segments, and below a composite of only two shell segments pipe section 2. Of course, pipe sections can also consist of five or more segments, but this increases the effort in assembling.

In this context, it is expressly stated that the invention also includes a silencer produced according to the invention, which is composed of at least two shell segments.

Fig. 6 finally shows a vehicle 24, with a turbocharger 23 and a connected to the pressure side of the turbocharger 23, inventive or inventively produced muffler. 1

The task underlying the independent inventive solutions can be taken from the description.

Above all, the individual figures shown embodiments may form the subject of independent, inventive solutions, as defined in the appended claims. The related objects and solutions of the present invention will be apparent from the detailed description of these figures, and defined by the appended claims.

REFERENCE NUMBERS

1

silencer

2

Inner pipe section

3

coat

4

casing segment

5

casing segment

6

casing segment

7

First opening

8th

Second opening

9

First end

10

Second end

11

First connection piece

12

Second connector

13

Axial edge

14

First resonance chamber

15

Second resonance chamber

16

Resonatorkammerwand

17

recess

18

recess

19

sheet metal piece

20

Flat sheet metal

21

Flange-shaped section

22

Apron-shaped section

23

turbocharger

24

vehicle

Claims (20)

1. Silencer (1), in particular a vehicle silencer, having an inner pipe section (2) and at least one resonator chamber (14, 15) formed outside the pipe section (2), wherein the pipe section (2) has in its shell (3) at least one opening (7, 8) that connects the interior of the pipe section (2) with the resonator chamber (14, 15), characterized in that the shell (3) of the inner pipe section is composed of at least three shell segments (4, 5, 6) arranged to be adjacent along the circumference of the pipe, which shell segments each extend in axial direction from a first connecting piece (11) to a second connecting piece (12), with first ends (9) of the shell segments (4, 5, 6) being connected with the first connecting piece (11) and second ends (10) of the shell segments (4, 5, 6), arranged opposite the first ends (9), being connected with the second connecting piece (12).
2. Silencer according to claim 1, characterized in that the shell (3) of the inner pipe section (2) is composed of three shell segments (4, 5, 6), each extending along the circumference of the pipe about essentially 120°.
3. Silencer according to claim 1 or 2, characterized in that the shell segments (4, 5, 6) are formed from individual, pre-bent pieces of sheet metal (19), preferably of stainless steel sheets.
4. Silencer according to one of the preceding claims, characterized in that the first ends (9) and/or the second ends (10) of the shell segments (4, 5, 6) are welded or connected in a force-fitting manner to the first and/or the second connecting piece (11, 12).
5. Silencer according to one of the preceding claims, characterized in that the first ends (9) and/or the second ends (10) of the shell segments (4, 5, 6) each have at least one flange-shaped section (21).
6. Silencer according to one of the preceding claims, characterized in that the first ends (9) and/or the second ends (10) of the shell segments (4, 5, 6) each have at least one skirt-shaped section (22), with the skirt-shaped section (22) resting against a connecting piece (12).
7. Silencer according to one of the preceding claims, characterized in that the axially running edges (13) of the adjacent shell segments (4, 5, 6) rest against one another in a loose manner, wherein preferably a slot which extends in axial direction is formed at least between two adjacent shell segments (4, 5, 6).
8. Silencer according to one of the preceding claims, characterized in that the cross-section of the shell segments (4, 5, 6) is, perpendicular with respect to the axial direction, arc-shaped, preferably circular-arc-shaped.
9. Silencer according to one of the preceding claims, characterized in that each shell segment (4, 5, 6) has at least one, preferably at least two, recesses (17, 18) forming the openings (7, 8) in the shell (3) of the inner pipe section (2).
10. Silencer according to one of the preceding claims, characterized in that the shell segments (4, 5, 6) forming the inner pipe section (2) are of the same size and same shape, wherein preferably shape, arrangement and size of the recesses (17, 18) are the same in all shell segments (4, 5, 6).
11. Silencer according to one of the preceding claims, characterized in that the at least one resonator chamber (14, 15) surrounds the inner pipe section (2) along its entire circumference, wherein preferably the inner pipe section (2) is completely surrounded by resonator chamber walls.
12. Silencer according to one of the preceding claims, characterized in that the silencer (1) has at least two resonator chambers (14, 15) which are separated from one another and arranged to be one behind the other in axial direction, with the shell (3) of the inner pipe section (2) having first openings (7) which open into the first resonator chamber (14), and second openings (8) which open into the second resonator chamber (15).
13. Vehicle, in particular road vehicle, having a silencer (1), in particular a turbocharger silencer, which is arranged on the discharge side of a turbocharger (23), characterized in that the silencer (1) is a silencer according to one of the preceding claims.
14. Method for manufacturing a silencer (1), in particular a vehicle silencer, having an inner pipe section (2) and at least one resonator chamber (14, 15) formed outside the pipe section (2), wherein the pipe section (2) has in its shell (3) at least one opening (7, 8) that connects the interior of the pipe section (2) with the resonator chamber (14, 15), characterized in that shell segments (4, 5, 6) are prefabricated as individual components and independently of the resonator walls surrounding the resonator chamber(s) on the outside, and that the shell (3) of the inner pipe section (2) is formed by assembling the prefabricated shell segments (4, 5, 6), wherein the shell (3) of the inner pipe section (2) is composed of at least three shell segments (4, 5, 6), and with the shell segments (4, 5, 6) being arranged to be distributed along the circumference of the pipe and each extending in axial direction from a first connecting piece (11) to a second connecting piece (12), and that first ends (9) of the shell segments (4, 5, 6) are connected with the first connecting piece (11), and second ends (10) of the shell segments (4, 5, 6), lying opposite the first ends (9), are connected with the second connecting piece (12).
15. Method according to claim 14, characterized in that the shell (3) of the inner pipe section (2) is composed of three shell segments (4, 5, 6), each extending along the circumference of the pipe about essentially 120°.
16. Method according to claim 14 or 15, characterized in that each of the shell segments (4, 5, 6) are manufactured by way of a bending process of a piece of sheet metal (19), preferably a stainless steel sheet, with the shell segments (4, 5, 6) being brought into a shape having an arc-shaped, preferably circular-arc-shaped, cross-section by way of the bending process.
17. Method according to claim 16, characterized in that prior to the bending process, the pieces of sheet metal (19) are cut out of an essentially planar metal sheet (20) to have the size of the shell segments (4, 5, 6), wherein preferably the metal sheet (20) is provided having the shape of a strip of sheet metal, the width of which already corresponds to the width of the shell segment (4, 5, 6) to be prefabricated.
18. Method according to one of claims 16 to 17, characterized in that prior to the bending process, recesses (17, 18) are brought into the piece of sheet metal (19), which recesses form openings (7, 8) in the shell (3) of the inner pipe section (2) when the shell segments (4, 5, 6) are in their assembled state, wherein preferably the formation of the recesses (17, 18) is performed by laser machining.
19. Method according to one of claims 14 to 18, characterized in that at least one flange-shaped section (21) and/or at least one skirt-shaped section (22) is formed on each of the first ends (9) and/or second ends (10) of the shell segments (4, 5, 6).
20. Method according to one of claims 14 to 19, characterized in that the first ends (9) and/or the second ends (10) of the shell segments (4, 5, 6) are welded or connected in a force-fitting manner to the first and/or the second connecting piece (11, 12).

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