The present invention relates to a muffler for an exhaust system of an internal combustion engine. The invention also relates to an exhaust system equipped with such a muffler.
In dual-flow exhaust systems, i.e., in exhaust systems having two exhaust lines with exhaust gas flowing through them in parallel, it is customary for a muffler to be provided at approximately half the distance between the internal combustion engine and the tailpipes opening into the environment, with the two exhaust lines being assigned jointly to the muffler, which is usually referred to as a central muffler. If the exhaust system together with the internal combustion engine is accommodated in a motor vehicle, the two exhaust lines may be installed in a type of tunnel along the undercarriage of the vehicle when the internal combustion engine is mounted in the front end, said tunnel optionally being open at the bottom. The dimensions of this tunnel must be selected so that a critical thermal load on the tunnel walls can be prevented. At the same time, an attempt is made to make the dimensions of the tunnel as small as possible to thereby minimize any negative effects in the interior of the vehicle. Design space problems may occur, for example, if the dual-flow exhaust system must be equipped with a muffler in the area of the tunnel.
A traditional muffler, which is tied jointly into two parallel exhaust lines, usually includes a housing with two side walls opposite one another in the longitudinal direction of the exhaust lines. The two exhaust lines lead into the one side wall and out of the other side wall. A jacket of the housing surrounds in the circumferential direction the two side walls and thus the two exhaust lines inasmuch as they are continued in the interior of the housing. In any case, the cross section of the housing protrudes over the individual cross sections of the exhaust lines with regard to the longitudinal direction of the exhaust lines in each radial direction. To be able to accommodate such a muffler in the tunnel, the tunnel must be enlarged accordingly in the area of the muffler. Such a local increase in the size of the tunnel leads to unwanted negative effect on the interior of the vehicle and is also associated with an increased manufacturing complexity.
The invention is based on the general idea of integrating two pipes through which exhaust can flow and to which the exhaust lines are connectable or which are formed by longitudinal sections of the exhaust lines into the housing of the muffler in such a way that they form two exterior longitudinal side walls of the housing. In this way, the muffler is bordered by the aforementioned pipes in the area of these longitudinal side walls, so that the housing is at any rate arranged between the two pipes and thus between the two exhaust lines. In a plane containing the two pipes, i.e., the two exhaust lines, the muffler thus needs no more room than the two pipes without the housing and/or the two exhaust lines without the muffler anyway.
To provide the muffler with a damper space, which has a volume equal to the volume of the traditional central muffler, the muffler must be lengthened accordingly in the longitudinal direction of the pipes, i.e., the exhaust lines.
In an embodiment of the invention, the housing may be designed so that it is situated inside an outside contour of at least one of the pipes or protrudes maximally by 20% beyond this outside contour in a viewing direction oriented from one pipe to the other pipe. As a result of this design, the muffler needs only slightly more space or none at all across the longitudinal direction of the pipes, i.e., the exhaust lines and across the aforementioned viewing direction than do the pipes without the housing and/or the exhaust lines without the muffler. For installation of the exhaust system in a vehicle, this means that the tunnel need be enlarged only slightly in this direction or not at all.
It is self-evident that the aforementioned features and those yet to be explained below may be used not only in the particular combination given but also in other combinations or alone without going beyond the scope of the present invention.
Preferred exemplary embodiments of the invention are illustrated in the drawings and are explained in greater detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.
The figures show schematically:
a-5c show simplified sectional views of the muffler according to sectional lines V in
According to
The muffler 5 also has a housing 8 which contains a damper space 9. This damper space 9 is arranged between the two pipes 6, 7. The damper space 9 may be filled at least partially with a damper material (not shown here) which has an absorbing effect for airborne sound.
The housing 8 has two longitudinal side walls 10, 11 which extend in the longitudinal direction of the pipes 6, 7, i.e., the exhaust lines 2, 3 prevailing in the area of the muffler 5. These longitudinal side walls 10, 11 of the housing 8 are formed according to this invention by wall sections (not identified separately) of the two pipes 6, 7. Said wall sections form the longitudinal side walls 10, 11, so these wall sections are also referred to below as 10 and/or 11. These wall sections 10, 11 are designed to be permeable for airborne sound, so that the airborne sound conveyed in the exhaust lines 2, 3 may pass through the wall sections 10, 11 into the damper space 9 to be dampened there in a suitable manner, e.g., by means of a damper material. Due to this design, the two pipes 6, 7 form the lateral borders of the housing 8 and/or the muffler 5 in the area of the longitudinal side walls 10, 11.
In the embodiments shown here, the two pipes 6, 7 each have a linear course, at least in a longitudinal section assigned to the housing 8. Such a linear course simplifies the manufacture of the muffler 5. In the embodiments in
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In other embodiments, the housing 8 may also protrude beyond the outside contour 14 in said viewing direction 13, by a maximum of 20% in particular. This yields only a slight increase in space required in the height direction of the muffler 5 in comparison with an embodiment of the exhaust system 1 without the muffler 5.
As already mentioned above, the wall sections 10, 11 of the pipes 6, 7 which form the longitudinal side walls 10, 11 of the housing 8 are designed to be permeable for airborne sound. This airborne sound permeability is achieved, for example, by the fact that the respective wall section 10 and/or 11 is perforated according to
According to
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In the embodiment illustrated in
In the embodiments according to
Number | Date | Country | Kind |
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10 2005 052 619.5 | Feb 2005 | DE | national |