Exhaust gas system

• US 20040006970A1
• Filed: 07/03/2003
• Published: 01/15/2004
• Est. Priority Date: 07/10/2002
• Status: Active Grant

• Current Assignee: Eberspacher Exhaust Technology GmbH & Co. KG (Eberspächer Gruppe GmbH & Co. KG)
• Original Assignee: J. Eberspacher GmbH & Co. KG
• Inventors: Worner, Siegfried, Sigel, Ulrich
• Granted Patent: US 6,938,729 B2
• Time in Patent Office: Days
• US Class Current: 60/272
• CPC Class Codes: F01N 1/166 for changing gas flow path through the silencer or for adjusting the dimensions of a chamber or a pipe F01N1/165 takes precedence
• CPC Class Codes: F01N 13/011 having two or more purifying devices arranged in parallel
• CPC Class Codes: F01N 13/02 having two or more separate silencers in series
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector

Abstract

An exhaust gas system for an internal combustion engine, in particular, of a motor vehicle has two mufflers through which the exhaust gas is able to flow in a parallel fashion. A switching unit makes it possible to selectively convey the exhaust gas flow of the internal combustion engine only or almost exclusively through the first muffler, or only or almost exclusively through the second muffler, or through both mufflers in a parallel fashion. The two mufflers are realized differently with respect to their muffling effect and/or flow resistance.

Claims

1. An exhaust gas system for an internal combustion engine (1), in particular, of a motor vehicle,

comprising two mufflers (3, 4), through which the exhaust gas is able to flow in a parallel fashion,

wherein a switching unit (11) is provided which makes it possible to selectively convey the exhaust gas flow of the internal combustion engine (1) only or almost exclusively through the first muffler (3) or only or almost exclusively through the second muffler (4) or through both mufflers (3, 4) in a parallel fashion, and

wherein the two mufflers (3, 4) are realized differently with respect to their muffling effect and/or flow resistance.

2. The exhaust gas system according to claim 1, characterized in that the first muffler (3) has a higher muffling effect than the second muffler (4).

3. The exhaust gas system according to claim 1, characterized in that the second muffler (4) has a lower flow resistance than the first muffler (3).

4. The exhaust gas system according to claim 1, characterized in that the first muffler (3) is designed for achieving an optimized muffling effect while the second muffler (4) is designed for achieving an optimized power of the internal combustion engine.

5. The exhaust gas system according to claim 1, characterized in that the first muffler (3) is designed for muffling low frequencies while the second muffler (4) is designed for muffling high frequencies.

6. The exhaust gas system according to claim 1, characterized in that a control device (14) is provided which actuates the switching unit (11) in dependence on the engine load and/or the speed of the internal combustion engine (1).

7. The exhaust gas system according to claim 6, characterized in that the control device (14) actuates the switching unit (11) in such a way that the exhaust gas

only or predominantly flows through the first muffler (3) in a low speed range,

only or predominantly flows through the second muffler (4) in a medium speed range, and

flows through both mufflers (3, 4) in a parallel fashion in an upper speed range.

8. The exhaust gas system according to claim 7, characterized in that the control device (14) actuates the switching unit (11) in such a way that

at least 80% or at least 90% of the exhaust gas flow through the first muffler (3) in the lower speed range and

at least 80% or at least 90% of the exhaust gas flow through the second muffler (4) in the medium speed range.

9. The exhaust gas system according to claim 1, characterized in that the switching unit (11) is realized in such a way that, when the second muffler (4) is activated, the first muffler (3) can be additionally activated continuously or in several stages.

10. The exhaust gas system according to claim 1, characterized in that two parallel exhaust gas pipe assemblies (5, 6) are provided, wherein one of the mufflers (3, 4) is respectively arranged in each exhaust gas pipe assembly, and wherein the exhaust gas pipe assemblies are connected to one another in a communicating fashion upstream of the mufflers (3, 4).

11. The exhaust gas system according to claim 10, characterized in that both exhaust gas pipe assemblies (5, 6) branch off a common master pipe that is connected to the internal combustion engine (1).

12. The exhaust gas system according to claim 10, characterized in that both exhaust gas pipe assemblies (5, 6) are separately connected to the internal combustion engine (1) and contain a common mixing chamber (7) between the internal combustion engine (1) and the mufflers (3, 4), wherein the two exhaust gas pipe assemblies (5, 6) communicate with one another via said mixing chamber.

13. The exhaust gas system according to claim 10, characterized in that a third muffler (8) is provided, wherein the two exhaust gas pipe assemblies (5, 6) communicate with one another in this third muffler.

14. The exhaust gas system according to claim 13, characterized in that the switching unit (11) is integrated into the third muffler (8).

15. The exhaust gas system according to claim 1, characterized in that the switching unit (11) contains two switching elements (12, 13) that are respectively assigned to the first and the second muffler (3, 4) and designed for opening and/or closing the exhaust gas path leading to the assigned muffler (3, 4).

16. The exhaust gas system according to claim 15, characterized in that the two switching elements (12″

, 13″

) are respectively integrated into the first and the second muffler (3, 4).

17. The exhaust gas system according to claim 1, characterized in that the first muffler (3) and the second muffler (4) are respectively realized in the form of rear mufflers.

18. The exhaust gas system according to claim 13, characterized in that the third muffler (8) is realized in the form of a central muffler and/or a front muffler.