Muffler

Abstract

The present invention relates to a muffler for an exhaust device of an internal combustion engine, which comprises a muffler housing having at least two interconnected housing covers that enclose and define an internal muffler space. Each housing cover has a housing cover - connecting edge extending in a direction away from the internal muffler space, and the housing covers are joined to each other in a material - locking manner in the region of their mutually opposed housing cover - connecting edges. An isolation assembly is provided in the internal muffler space and at least partially covers the inner side of at least one of the housing covers. It is characterized in that the isolation assembly has at least one isolation cover, which includes an isolation cover - connecting edge extending in a direction away from the internal muffler space. The at least one isolation cover is arranged with its isolation cover - connecting edge between the mutually opposed housing cover - connecting edges of the housing covers and is joined to the housing cover - connecting edge of the housing cover in a material - locking manner in the region of the isolation cover - connecting edge.

Description

Field of the Invention

[0001] The present invention relates to a muffler for an exhaust device of an internal combustion engine. Background Art

[0002] A muffler for an exhaust device of an internal combustion engine according to the preamble of claim 1 is known from EP 1 512 852 B1. The muffler housing of the muffler is constructed by means of two housing covers formed from formed sheet material. The two housing covers each have an arched cover body and a housing cover - circumferential edge extending outward from the cover body and including a abutment surface. The housing cover - circumferential edges of the two housing covers are positioned opposite each other under an intermediate support part of an inner plate that divides the inner space of the muffler housing into two chambers and are connected to each other by laser welding. The inner plate and one of the housing covers together form an inlet region through which the exhaust gas flows into one of the chambers. The inner plate and the other housing cover of the two housing covers together form an outlet region through which the exhaust gas exits from the other chamber of the two chambers. The two chambers are connected to each other by means of a plurality of openings formed in the inner plate.

[0003] In the chamber into which the exhaust gas enters through the inlet region in the two chambers, a layer covering the inner surface of the housing cover that outwardly defines the chamber of a heat insulation device made of a high - density fiber material is placed. The heat insulation device can be covered on at least one side by a diaphragm of rust - resistant steel. In the chamber that is heat - insulated with respect to the housing cover that defines the chamber by means of the heat insulation device, a fiber material having a lower fiber density relative to such a heat insulation device is also arranged. Summary of the Invention

[0004] The object of the present invention is to provide a muffler for an exhaust device of an internal combustion engine that can achieve heat insulation of the muffler housing in a structurally simple and easily manufacturable design.

[0005] According to the present invention, this object is solved by a muffler for an exhaust device of an internal combustion engine, the muffler comprising a muffler housing having at least two housing covers that enclose and define an inner space of the muffler and are connected to each other. Each housing cover has a housing cover - connection edge extending in a direction away from the inner space of the muffler, and the housing covers are connected to each other in a material - locking manner in the region of their mutually opposite housing cover - connection edges. And an insulating assembly is provided in the inner space of the muffler that at least partially covers the inner side of at least one of the housing covers.

[0006] The muffler is characterized in that the isolation assembly has at least one isolation cover, the isolation cover includes an isolation cover - connecting edge extending in a direction away from the internal space of the muffler, and the at least one isolation cover is arranged with its isolation cover - connecting edge between the mutually opposed housing cover - connecting edges of the housing cover and is connected to the housing cover - connecting edge of the housing cover by material locking in the region of the isolation cover - connecting edge.

[0007] In the muffler constructed according to the invention, a stable, simple and low - cost manufacturable structure is achieved by using at least three cover - shaped and mutually connectable components, namely the housing cover and the isolation cover, wherein a fixed and especially also sealed connection for the exhaust discharge of the three cover - shaped components is produced by material locking including these three components. Other measures for integrating heat - insulating devices for at least one of the two housing covers surrounding and defining the internal space of the muffler are not necessary.

[0008] The material - locking structure connecting the isolation cover - connecting edge and the housing cover - connecting edge of the housing cover may include a weld seam preferably extending substantially uninterruptedly along the housing cover - connecting edge and the isolation cover - connecting edge. With this single three - body seam, for example, a fixed connection of the three cover - shaped components of the muffler is achieved in a single welding process.

[0009] In order to provide a sufficiently large volume of the internal space of the muffler, at least one of the housing covers, preferably each housing cover, may at least have an arched housing cover body surrounded by its housing cover - connecting edge and surrounding and defining the internal space of the muffler, and the at least one isolation cover may have an arched isolation cover body surrounded by its isolation cover - connecting edge.

[0010] In order to avoid collision noise and to provide good heat insulation, it is proposed that the isolation cover body and the housing cover body of at least one of the housing covers are arranged at a distance from each other. Thus, a gap - shaped intermediate space is formed between the isolation cover body and the housing cover body of at least one of the housing covers, and the intermediate space provides an isolation layer with the gas accumulated therein. It should be noted that while maintaining such an intermediate space, the isolation cover body and the housing cover body of at least one of the housing covers may be in contact with each other locally, for example, in the region of a protruding forming part provided thereon, in order to achieve a defined mutual support. In such a region, these cover bodies may be fixedly connected to each other by welding, for example.

[0011] A simple and low - cost manufacturable design and especially a design particularly suitable for implementing the welding process can be set in such a way that the housing cover and the isolation cover are provided by sheet metal forming parts.

[0012] For a defined flow guidance in the interior space of the muffler, an exhaust gas flow volume can be formed between one of the separating cover and the housing cover, and the exhaust gas flow volume is divided into a plurality of chambers by at least one intermediate wall. Here, the at least one intermediate wall can be held clamped between the separating cover and the at least one of the housing covers. In this way, no additional measures are required to hold such an intermediate wall in a predetermined installation position in the interior space of the muffler. Furthermore, by clamping one or more such intermediate walls, a defined tensioning of the separating cover with respect to the housing cover is also achieved, so that in practice, vibration excitations that cause noise or damage in the muffler, especially in the separating cover, can be excluded.

[0013] In order to be able to adjust a defined silencing characteristic in the muffler, it is proposed that the at least one separating cover extends from a longitudinal end region of the muffler housing up to an intermediate wall and that the at least one of the housing covers in the housing cover is covered on its inner side in the region extending between the one longitudinal end region of the muffler housing and this intermediate wall, and in the region extending between this intermediate wall and the other longitudinal end region of the muffler housing, the at least one of the housing covers in the housing cover is not covered on its inner side by the at least one separating cover. Furthermore, it can be provided for this purpose that a chamber at least partially filled with sound-insulating material is formed between this intermediate wall and the other longitudinal end region of the muffler housing.

[0014] In order to introduce the exhaust gas into the muffler and to discharge the exhaust gas from the muffler, at least one exhaust gas inlet pipe open towards the interior space of the muffler and at least one exhaust gas outlet pipe open towards the interior space of the muffler can be provided. In order to achieve a fixed connection of these pipes to the muffler housing, it is proposed that at least one of the exhaust gas inlet pipe and the exhaust gas outlet pipe is preferably connected to the muffler housing in a material-locking manner in the region of a pipe receiving opening formed between the separating cover-connection edge and the housing cover-connection edge of one of the housing covers, or / and at least one of the exhaust gas inlet pipe and the exhaust gas outlet pipe is preferably connected to the muffler housing in a material-locking manner in the region of a pipe receiving opening formed between the housing cover-connection edges of the two housing covers.

[0015] The invention also relates to an exhaust gas device for an internal combustion engine, especially in a motor vehicle, which exhaust gas device includes at least one muffler according to one of the preceding claims. Description of the Drawings

[0016] The invention will now be described in detail with reference to the drawings. In the drawings:

[0017] Figure 1 A side view of a muffler of an exhaust gas device for a motor vehicle is shown;

[0018] Figure 2Shown in the case of removing the upper housing cover is a top view of the muffler along viewing direction II to Figure 1 ;

[0019] Figure 3 Shown is Figure 1 an exploded view of the muffler;

[0020] Figure 4 Shown is Figure 1 an enlarged view of detail IV, which vividly illustrates Figure 1 the connection of the two housing covers and the isolation cover of the muffler. DETAILED DESCRIPTION

[0021] Figures 1 to 3 Shown is a muffler for an exhaust device 12 of an internal combustion engine in a vehicle, generally designated 10. The muffler 10 includes a muffler housing 14 having housing covers 16 and 18. Each housing cover 16, 18 provided as a sheet metal forming part has a housing cover body 22, 24, which is arched outwardly with respect to the muffler internal space 20 defined by the housing covers 16, 18. Each housing cover body 22, 24 is surrounded by a housing cover - connection edge 26, 28 extending outwardly with respect to the muffler internal space 20. The two housing covers 16, 18 are opposed to each other with their housing cover - connection edges 26, 28 and are connected in the region of the housing cover - connection edges 26, 28 in the manner described below.

[0022] In the muffler internal space 20 defined by the two housing covers 16, 18, an isolation assembly 32 is provided by an isolation cover 30 formed as a sheet metal forming part. The isolation cover 30 has an arched isolation cover body 34 and an isolation cover - connection edge 36 surrounding the isolation cover body. The isolation cover - connection edge 36 also extends outwardly with respect to the muffler internal space 20 and is located between the housing cover - connection edges 26, 28 in the assembled state.

[0023] In Figure 3 it can be seen that the isolation cover body 30 is adapted in terms of its arched structure to the arched structure of the housing cover 18. In the assembled state, the isolation cover body 34 of the isolation cover 30, which is substantially adapted in its shaping to the shaping of the arched housing cover body 24 of the housing cover 18, is spaced apart from the housing cover body 24 when the isolation cover - connection edge 36 is positioned between the housing cover - connection edges 26, 28, so that a gap - like intermediate space 38 is formed between the isolation cover body 34 and the housing cover body 24.

[0024] The partition hood 30 extends within the inner space 20 of the housing hood defined and surrounded by the housing hoods 16, 18 from the first longitudinal end region 40 of the muffler housing 14 up to one of the three intermediate walls 42, 44, 46 provided in the muffler inner space 20. In the region between the first longitudinal end region 40 of the muffler housing 14 and the intermediate wall 42, the partition hood 30 covers the inner side 48 of the housing hood 18 while maintaining the intermediate space 38.

[0025] Through the intermediate walls 42, 44, 46, the muffler inner space 20 is divided into four chambers 50, 52, 54, 56. The chamber 50 extends substantially between the intermediate wall 42 and the second longitudinal end region 58 of the muffler housing 40. The chamber 52 is substantially between the two intermediate walls 42, 44. The chamber 54 is substantially between the two intermediate walls 44, 46, and the chamber 56 extends substantially between the intermediate wall 46 and the first longitudinal end region 40 of the muffler housing 14. Through the openings provided in the intermediate walls 42, 44, 46, these chambers 50, 52, 54, 56 are connected to each other.

[0026] The intermediate walls 44, 46 are in the region where the partition hood 30 covers the inner side 48 of the housing hood 18. Thus, there is no direct contact between the intermediate walls 44, 46 and the housing hood 18. The intermediate walls 44, 46 are thus held between the partition hood 30 and the housing hood 16. For this purpose, inwardly projecting, rib-shaped protruding formations arranged in pairs with each other can be formed on the partition hood 30 on the one hand and on the housing hood 16 on the other hand, and the intermediate walls 44, 46 are fixedly held between the protruding formations and are thus clamped between the partition hood 30 and the housing hood 16 in all directions of movement.

[0027] The intermediate wall 42 can be positioned such that it is connected to the partition hood 30 in the direction from the first longitudinal end region 40 of the muffler housing 14 towards the second longitudinal end region 58 and is thus held in the region of the inwardly projecting, rib-shaped protruding formations arranged in pairs with each other and provided thereon between the housing hoods 16, 18. In order to avoid noise that may be generated due to mutual collision, a gap-shaped intermediate space can be formed between the end region 60 of the partition hood 30 close to the intermediate wall 42 and the intermediate wall 42. It should be noted that alternatively, for example, when two inwardly projecting, rib-shaped protruding formations for receiving the intermediate wall are also arranged on the partition hood 30 at the intermediate wall 42, the intermediate wall 42 can also be held between the housing hood 16 and the partition hood 30.

[0028] The muffler 10 further includes an inlet pipe 62 and an outlet pipe 64. The inlet pipe 62 is led into the muffler internal space 20 in the region of a pipe receiving opening 66 formed in the muffler housing 14 and passes through the intermediate walls 44, 46. The inlet pipe 62 has perforations 68 in its longitudinal region between the intermediate walls 44, 46, through which the inlet pipe 62 opens towards the chamber 54. The inlet pipe 62 opens towards the chamber 56 at its end in the muffler internal space 20.

[0029] The outlet pipe 64 is led into the muffler internal space 20 in the region of a pipe receiving opening 70 and passes through the intermediate walls 42, 44, 46. In the region of the chamber 56, the outlet pipe 64 opens towards the chamber 56 at its end in the muffler internal space 20.

[0030] The outlet pipe 64 extends through a sound insulating material 72 provided in the chamber 50 in its longitudinal region passing through the chamber 50. The sound insulating material can be formed in a block shape and be constructed of a foamed or fibrous material. Alternatively, the sound insulating material 72 can also be formed as a lining which covers the housing covers 16, 18 on their respective inner sides in the region of the chamber 50 without occupying the entire volume or substantially the entire volume of the chamber 50.

[0031] The pipe receiving opening 66 for the inlet pipe 62 is in a region of the muffler housing 14 in which the isolation cover 30 covers the housing cover 18 on its inner side 48. Thus, the pipe receiving opening 66 is substantially formed between the housing cover - connection edge 26 of the housing cover 16 and the isolation cover - connection edge 36 of the isolation cover 30.

[0032] The pipe receiving opening 66 for the inlet pipe 62 is substantially centered between the two longitudinal end regions 40, 58 of the muffler housing 14, while the pipe receiving opening 70 for the outlet pipe 64 is provided at the second longitudinal end region 58 of the muffler housing 14 and is thus in a region in which the housing cover 18 is not covered by the isolation cover 30 and thus the isolation cover - connection edge 36 is not positioned between the housing cover - connection edges 26, 28. The pipe receiving opening 70 for the outlet pipe 64 is thus formed between the housing cover - connection edges 26, 28 of the housing covers 16, 18.

[0033] When assembling the muffler 10, the muffler insert 74 can be constructed first. The muffler insert includes intermediate walls 42, 44, 46, sound-insulating material 72, an inlet pipe 62 passing through the intermediate walls 44, 46, and an outlet pipe 64 passing through the sound-insulating material 72 and the intermediate walls 42, 44, 46. To establish a fixed connection, the inlet pipe 62 and the outlet pipe 64 can be connected to the intermediate walls 42, 44, 46 through which they pass, for example, by material locking (such as welding) or / and by press fitting. Then, the muffler insert 74 can be placed, for example, in the housing covers 16, 18 that are not covered by the isolation cover 30 on their inner sides. In the example shown, this is the housing cover 16. After the muffler insert 74 is positioned in the housing cover 16, for example, the isolation cover 30 can be put on the muffler insert 74 first, so that the isolation cover locally covers the housing-connection edge 26 of the housing cover 16 with its isolation-connection edge 36 and together with the housing-connection edge 26 surrounds the inlet pipe 62 in the region of the pipe receiving opening 66 with its isolation-connection edge 36.

[0034] In the next working step, another housing cover, namely the housing cover 18 in the example shown, can be put on, so that it covers the isolation cover 30 or rather the housing cover 16 and the muffler insert 74 that has already been positioned on the housing cover 16. The housing-connection edge 18 of the housing cover 18 is then on the isolation-connection edge 36 in the region where the isolation-connection edge 36 of the isolation cover covers the housing-connection edge 26 of the housing cover 16, and is directly opposite or on the housing-connection edge 26 of the housing cover 16 in the region where the housing-connection edge 26 is not covered by the isolation-connection edge 36. To avoid creating a gap-like intermediate space in this region, a stepped transition to the backward-offset region of the corresponding housing-connection edge can be formed in at least one of the housing covers 16, 18 in the region of its housing-connection edges 26, 28, so as to sufficiently create a receiving space for the isolation-connection edge 36 in the region where the isolation-connection edge 36 is to be positioned between the housing-connection edges 26, 28.

[0035] After the housing cover 18 is put on, the outlet pipe 64 is held between the housing-connection edges 26, 28 of the housing covers 16, 18 in the region of the pipe receiving opening 70, and the intermediate walls 42, 44, 46 are held between the isolation cover 30 and the housing cover 16 or between the housing cover 18 and the housing cover 16.

[0036] In a subsequent work process, the housing cover-connection edges 26, 28 between which the separator cover-connection edge 36 is locally received can be interconnected with one another by material locking, preferably welding. For this purpose, a circumferentially preferably surrounding weld seam 76 is formed in order to obtain an airtight closure. In addition, the inlet pipe 62 and the discharge pipe 70 are connected to the surrounding connection edges in the regions where they are respectively located in the pipe receiving openings 66 or 70 by material locking, preferably welding. Also here, in order to obtain an airtight closure, weld seams that completely surround the respective pipe receiving openings 66, 70 can be formed. In the region of the pipe receiving opening 66, where the pipe receiving opening 66 is defined by being surrounded by the separator cover-connection edge 36, a connection is also produced between the separator cover-connection edge 36 and the housing cover-connection edge 28 of the housing cover 18 that is shaped to fit the separator cover-connection edge.

[0037] In the previously described construction of the muffler, local heat insulation of one of the housing covers is achieved by arranging the separator cover in the muffler interior space defined by the housing cover, for which only the insertion of a sheet metal forming part is required. The gap-shaped intermediate space formed between the separator cover and the housing cover locally covered by it serves for heat insulation to the outside without the need for additional structural measures.

[0038] Finally, it should be noted that, without departing from the principles of the present invention, of course the previously described muffler can be implemented differently in different aspects. Thus, for example, the separator cover can cover one of the housing covers on its entire inner side. The separator cover can be configured in multiple parts, and one separator cover can be arranged for each of the two housing covers, so that then the two separator cover-connection edges that are in contact with each other if necessary are positioned between the housing cover-connection edges of the housing covers that are to be opposed to each other. Insulation material, such as an insulation pad, i.e., a fibrous material, can be provided between the separator cover and the housing cover covered by the separator cover on its inner side in order to further improve heat insulation.

[0039] Furthermore, it should be noted that, for example, two pipes, i.e., the inlet pipe and the discharge pipe, can be connected to the housing cover in a region where at least one housing cover is covered by the separator cover. Alternatively, the two pipes can be connected to the muffler housing in a region where no housing cover is covered by the separator cover.

[0040] The muffler insert to be arranged in the muffler interior space can be implemented differently from that shown in the illustrated design example. It can include more or fewer intermediate walls. In addition, the muffler insert can be constructed such that a Helmholtz resonator is formed in the muffler interior space, and multiple inlet pipes or / and multiple discharge pipes can be provided in order to introduce exhaust gas into the muffler or discharge it from the muffler.

Claims

1. A muffler for an exhaust device of an internal combustion engine, the muffler comprising a muffler housing (14), the muffler housing having at least two housing covers (16, 18), the at least two housing covers surrounding and defining a muffler internal space (20) and being connected to each other, each of the at least two housing covers (16, 18) having a housing cover - connection edge (26, 28) extending in a direction away from the muffler internal space (20), and the at least two housing covers (16, 18) being joined to each other in a material - locking manner in the region of their mutually opposed housing cover - connection edges (26, 28), and an isolation assembly (32) being provided in the muffler internal space (20) and at least partially covering the inner side (48) of one of the at least two housing covers (16, 18). Wherein, the isolation assembly (32) has at least one isolation cover (30), the at least one isolation cover having an isolation cover - connection edge (36) extending in a direction away from the muffler internal space (20), the at least two housing covers (16, 18) and the isolation cover (30) being provided by sheet - metal formed parts, the at least one isolation cover (30) being arranged with its isolation cover - connection edge (36) between the mutually opposed housing cover - connection edges (26, 28) of the at least two housing covers (16, 18) and being joined to the housing cover - connection edges (26, 38) of the at least two housing covers (16, 18) in a material - locking manner in the region of the isolation cover - connection edge (36), an exhaust gas flow volume being formed between the isolation cover (30) and the other of the at least two housing covers (16, 18), the exhaust gas flow volume being divided into a plurality of chambers (50, 52, 54, 56) by at least one intermediate wall (42, 44, 46), and at least one intermediate wall (44, 46) being clamped and held between the at least one isolation cover (30) and the other of the at least two housing covers (16, 18).

2. The muffler according to claim 1, characterized in that, the material - locking structure connecting the isolation cover - connection edge (36) to the housing cover - connection edges (26, 28) of the at least two housing covers (16, 18) comprises a weld seam (76) along the housing cover - connection edges (26, 28) and the isolation cover - connection edge (36).

3. The muffler according to claim 2, characterized in that, the weld seam (76) extends without interruption.

4. The muffler according to any one of claims 1 to 3, characterized in that, at least one of the at least two housing covers (16, 18) comprises an arched housing cover body (22, 24) surrounded by its housing cover - connection edges (26, 28) and surrounding and defining the muffler internal space (20), and the at least one isolation cover (30) has an arched isolation cover body (34) surrounded by its isolation cover - connection edge (36).

5. The muffler according to claim 4, characterized in that, Each of the at least two housing covers (16, 18) includes an arched housing cover body (22, 24) surrounded by its housing cover - connecting edge (26, 28) and enclosing the muffler interior space (20).

6. The muffler according to one of claims 1 - 3, characterized in that the partition cover body (34) and the housing cover body (24) of one of the at least two housing covers (16, 18) are arranged at a distance from each other.

7. The muffler according to one of claims 1 - 3, characterized in that the at least one partition cover (30) extends from a longitudinal end region (40) of the muffler housing (14) to an intermediate wall (42) and covers one of the at least two housing covers (16, 18) in the region extending between the longitudinal end region (40) of the muffler housing (14) and the intermediate wall (42) on the inner side (48) of the housing cover, and in the region extending between the intermediate wall (42) and another longitudinal end region (58) of the muffler housing (14), one of the at least two housing covers (16, 18) is not covered by the at least one partition cover (30) on its inner side (48).

8. The muffler according to claim 7, characterized in that a chamber (50) at least partially filled with sound - insulating material (72) is formed between the intermediate wall (42) and the other longitudinal end region (58) of the muffler housing (14).

9. The muffler according to one of claims 1 - 3, characterized in that at least one exhaust inlet pipe (62) opening towards the muffler interior space (20) and at least one exhaust outlet pipe (64) opening towards the muffler interior space (20) are provided, and at least one of the exhaust inlet pipe (62) and the exhaust outlet pipe (64) is connected to the muffler housing (14) in the region of a pipe receiving opening (66) formed between the partition cover - connecting edge (36) and the housing cover - connecting edge (26) of one of the at least two housing covers (16, 18) or / and at least one of the exhaust inlet pipe (62) and the exhaust outlet pipe (64) is connected to the muffler housing (14) in the region of a pipe receiving opening (70) formed between the housing cover - connecting edges (26, 28) of two of the at least two housing covers (16, 18).

10. The muffler according to one of claims 1 - 3, characterized in that At least one of the exhaust gas inlet pipe (62) and the exhaust gas outlet pipe (64) is connected to the muffler housing (14) by a material-locking connection in the region of the pipe receiving opening (66) formed between the isolation hood-connection edge (36) and the housing hood-connection edge (26) of one of the at least two housing hoods (16, 18), or / and at least one of the exhaust gas inlet pipe (62) and the exhaust gas outlet pipe (64) is connected to the muffler housing (14) by a material-locking connection in the region of the pipe receiving opening (70) formed between the housing hood-connection edges (26, 28) of the two housing hoods among the at least two housing hoods (16, 18).

11. An exhaust gas device for an internal combustion engine, the exhaust gas device comprising at least one muffler (10) according to one of claims 1 to 10.

12. The exhaust gas device according to claim 11, characterized in that the exhaust gas device is arranged in a motor vehicle.

Images