WO2019042556A1

WO2019042556A1 - Exhaust gas system and motor vehicle provided therewith

Info

Publication number: WO2019042556A1
Application number: PCT/EP2017/071894
Authority: WO
Inventors: Hannes Steinkilberg; Marianne Boudoy; M. Romain JOLY; Aurélie DEMONT; Stéphane NEZAN
Original assignee: Faurecia Emissions Control Technologies, Germany Gmbh
Priority date: 2017-08-31
Filing date: 2017-08-31
Publication date: 2019-03-07
Also published as: CN111051661A; US20200256227A1; DE112017007974A5

Abstract

The invention relates to an exhaust gas system (12) for an internal combustion engine of a motor vehicle. Said exhaust gas system comprises a singular exhaust gas inlet line (16), two exhaust gas outlet lines (18) connected in an exhaust gas conducting manner to the exhaust gas inlet line (16), and an active sound damping device which is connected in a sound-conducting manner to both exhaust gas outlet lines (18). The invention also relates to a motor vehicle having an exhaust gas system (12) of this type.

Description

Exhaust system and motor vehicle with an exhaust system

The invention relates to an exhaust system for an internal combustion engine of a motor vehicle.

In addition, the invention relates to a motor vehicle with an exhaust system. Exhaust systems with one or more tailpipes are known from the prior art, wherein a plurality of tailpipes are used when relatively large flow cross-sections are to be provided for an exhaust gas flow. Also, by means of the number of tailpipes, the external appearance of an associated motor vehicle can be designed. In this context, for example, particularly sporty motor vehicles often have two or more tailpipes.

Exhaust systems with more than one exhaust end pipe are also referred to as multi-flow.

Moreover, it is known from the prior art to provide exhaust systems with active sound attenuation devices so as to dampen noise emitted by the exhaust system to an environment or, ideally, to completely eliminate it.

Conventionally, the active sound damping devices for this purpose comprise a loudspeaker with whose help they generate sound which is superimposed on the sound carried by the exhaust gas flow. The superposition is ideally destructive, d. H. The aim is to superimpose the sound generated by the loudspeaker on the sound carried by the exhaust gas stream in opposite phase.

Multi-flow exhaust systems, which are equipped with active sound damping devices, are known for example from DE 100 85 230 B3, EP 2 915 967 A1 and DE 10 2012 200 712 A1. Each exhaust system is assigned an active sound damping device. Such exhaust gas Layers are therefore consuming in terms of sound attenuation devices in construction and thus relatively expensive.

In addition, multi-flow exhaust systems are known, which have several exhaust gas inlet pipes. Such exhaust systems thus have a plurality of exhaust gas inlets and a plurality of exhaust gas outlets. In particular, such exhaust systems are used in conjunction with internal combustion engines whose cylinders are arranged in V formation. Then, an exhaust gas inlet line is connected to the cylinders of a first cylinder bank exhaust-connected and another exhaust gas inlet line to the cylinders of a second cylinder bank. Such exhaust systems can also be equipped with a sound damping device, as can be seen for example from EP 2 818 654 A1 or EP 0 481 450 A1. The active sound damping devices act on the guided in both tailpipes exhaust. Such exhaust systems are particularly complex due to the two exhaust gas inlet lines. In addition, they are not very suitable for use in conjunction with inline engines.

The object of the invention is to provide an improved exhaust system which is multi-flow with respect to the exhaust exits and comprises an active sound damping device. The exhaust system should be as simple as possible in construction and in the production. In addition, an effective damping of the sound emitted via the exhaust gas flow to the surroundings should be ensured for all tailpipes. Furthermore, a motor vehicle is to be specified with such an exhaust system.

The object is achieved by an exhaust system of the aforementioned type, which comprises a singular exhaust gas inlet line, two exhaust gas outlet lines connected to the exhaust gas inlet line and an active silencing device that is sound conductively connected to both exhaust gas outlet lines. The exhaust gas inlet line is connected exhaust gas-conducting with the cylinders of the internal combustion engine. Between the internal combustion engine and the exhaust gas inlet line, further exhaust gas system elements can be arranged, which serve, for example, for exhaust gas purification. The exhaust gas outlet conduits are configured to direct exhaust gas to an environment of the exhaust gas system. They can also be referred to as exhaust tailpipes. An exhaust system according to the invention therefore combines a single exhaust gas inlet line and a single sound Damping device with two exhaust gas outlet pipes. The exhaust system is thus particularly simple in construction. In particular, it is possible to dispense with a second exhaust gas inlet line and / or a second active sound damping device in comparison with the prior art. The sound-conducting connection of the sound damping device with both exhaust gas outlet pipes also ensures effective sound damping.

The sound damping device can also be designed as a so-called sound actuator according to an embodiment of the invention, in which the sound design (alternatively or in addition to the sound attenuation) is an important aspect.

The active sound damping device may comprise a sound generating device, in particular a loudspeaker, which is arranged in a Schallerzeu- tion device housing. The sound generating device per se has a well-known and proven from the prior art construction. This makes it robust and reliable. Furthermore, it can be inexpensively manufactured or obtained on the market.

According to one variant, the exhaust gas inlet line is connected via a passive silencer exhaust gas conducting with the exhaust gas outlet. The passive silencer can be an end silencer. The passive silencer serves to reduce the sound emitted to an environment. The passive silencer and the active silencer thus serve the same purpose. In this case, the active sound damping device and the passive muffler can be coordinated. This can be done, for example, by designing the passive muffler to attenuate relatively low frequencies and the active muffler to attenuate relatively high frequencies. In summary, the passive silencer ensures particularly good damping of the sound emitted by the exhaust system to the environment.

The passive muffler preferably includes a muffler housing. In this case, the exhaust-gas inlet line and / or at least one of the exhaust-gas outlet lines, preferably both exhaust-gas outlet lines, can be or are arranged in sections within a silencer housing of the passive sound system. Damper run. The exhaust gas inlet conduit thus passes through a wall portion of the muffler housing. Seen from the inside of the muffler housing, the exhaust gas inlet line thus protrudes from a wall section of the muffler housing. The projecting section of the exhaust gas inlet line, that is to say the section of the exhaust gas inlet line extending inside the muffler housing, may comprise cross-sectional changes and / or orientation changes, for example in the form of bends. The same applies to the at least one exhaust gas outlet line or both exhaust gas outlet lines. The cross-sectional and / or orientation changes of the exhaust gas inlet and / or exhaust gas outlet conduits may be selected such that an improved damping effect is achieved by means of the passive silencer. Thus, the sound delivered to the environment of the exhaust system is particularly effectively damped.

In another variant, in which the active sound generating device is designed such that it completely or almost completely eliminates the sound emitted by the exhaust system to the environment, it is possible to dispense with a passive silencer. This is to be understood as complete elimination that the emitted sound is attenuated so that a predetermined limit is not exceeded. Such exhaust system is particularly simple and space-saving in construction.

In one embodiment, the two exhaust gas outlet lines to the exhaust gas inlet line or an exhaust gas intermediate line form a T-connection or a Y-connection, wherein the exhaust gas intermediate line is exhaust-conductively connected to both Abgasauslassleitungen and the exhaust gas inlet line. In the event that the exhaust system does not include a passive muffler, the exhaust outlet conduits preferably form a T or Y connection with the exhaust gas inlet conduit. If a passive muffler is used, the exhaust gas outlet lines preferably form a T or Y connection with the exhaust gas intermediate line. In this case, the exhaust gas intermediate line preferably runs completely within a silencer housing of the passive silencer and is thus connected in an exhaust gas-conducting manner via an internal volume of the passive silencer to the exhaust gas inlet line. The T or Y connection is preferably produced by welding or soldering the exhaust gas lines forming the T or Y connection, which are realized, for example, in the form of exhaust-gas-conducting pipes. implemented. It is thus ensured a simple and inexpensive construction of the exhaust system.

Both the T and Y connections are a combination of three pipe sections. They differ in the angles which the pipe sections, more precisely their center axes, occupy with one another. While in a T-joint two of the pipe sections have substantially a common central axis and the third pipe section is oriented substantially perpendicular to this central axis, the term Y-connection covers all connections of three pipe sections, which are not referred to as T-connection can.

According to a development, the two exhaust gas outlet lines are formed by opposite sections of a common exhaust gas outlet tube. In other words, the exhaust outlet pipe forms a T or Y connection in a middle section with the exhaust gas inlet line or the exhaust gas intermediate line. This T or Y joint divides the exhaust outlet pipe into two portions located on opposite sides of the T or Y joint, each of which constitutes an exhaust gas exhaust pipe. In the production of the exhaust system so only two pipes must be connected to each other, namely the exhaust gas inlet pipe or the exhaust gas intermediate line forming pipe and the common Abgasauslassrohr. As a result, the production of the exhaust system is particularly simple.

The active sound damping device can be connected sound conductively to the exhaust gas outlet lines via a sound transmission line, wherein the sound transmission line surrounds the exhaust gas inlet side ends of the exhaust gas outlet lines on the outside and is substantially concentric with the exhaust gas inlet side ends of the exhaust gas outlet lines. In the event that the exhaust gas outlet ducts are formed by a common exhaust gas outlet pipe, the sound transmission pipe surrounds a central portion of the common exhaust gas outlet pipe on the outside and is substantially concentric therewith. A diameter of the sound transmission line is therefore always larger than a diameter of the common exhaust gas outlet pipe or the exhaust gas inlet pipe in that region in which it surrounds the exhaust gas inlet side ends of the exhaust gas outlet pipes or the common exhaust gas outlet pipe on the outside. side ends of the exhaust outlet pipes. The axial ends of the sound injection rail thus form annular openings together with the exhaust gas outlet pipes or the common exhaust gas outlet pipe. These are preferably closed. Such a coupling is often referred to as a sourdine connection. Thus, a simple but effective way is given to inject sound emanating from the active sound damping device into the exhaust gas outlet lines.

The Schalleinkoppelleitung may extend at least partially within a muffler housing of the passive muffler. The sound injection line preferably runs partially within the silencer housing and partly outside. As a result, the exhaust system takes up only a small amount of space.

In addition, the exhaust gas intermediate line or the exhaust gas inlet line can pass through a wall of the sound transmission line. This has the consequence that the T or Y connection between the exhaust gas intermediate line or the exhaust gas inlet line and the two exhaust gas outlet lines lies within the sound transmission line. This too leads to a compact construction of the exhaust system.

According to one embodiment, at least one of the exhaust gas outlet lines, preferably both exhaust gas outlet lines, comprises a perforated section in the area encompassed by the sound transmission line. About the perforation of the perforated portion forming openings sound from the sound input line can get into the interior of the Abgasauslassleitung. Thus, the sound generated by the active silencing unit may interact with the exhaust gas carried in the exhaust outlet conduit and attenuate or eliminate altogether sound carried by the exhaust gas flow. If both exhaust outlet ducts comprise perforated sections, these may be designed differently, for example with regard to the number, size and arrangement of the perforations forming openings. The perforation can thus be designed so that a maximum damping effect is achieved with respect to the sound emitted by the exhaust system sound.

Advantageously, both exhaust gas outlet conduits comprise perforated sections and the perforated sections are on opposite sides of each other Exhaust passage or arranged on opposite sides of the exhaust gas inlet pipe. The perforated sections are thus also on opposite sides of the T or Y connection. It is achieved as a compact design of the exhaust system. Preferably, the active sound damping device is connected via a sound conductively sound conductively connected to the Schalleinkoppelleitung. Thus, the active sound damping device is arranged at a distance from the sound transmission line, which may correspond substantially to a length of the sound line. As a result, the active sound damping device is also spaced from the exhaust gas-carrying components of the exhaust system. As a result, the components of the active sound damping device can always be operated at a temperature which is significantly below the temperature of the exhaust gases carried in the exhaust system. This ensures a particularly reliable and durable function of the active sound damping device. The sound pipe can run outside of a silencer housing of the passive silencer. The sound conduction is thus also coupled outside of the muffler housing with the sound input line. As a result, a good compromise between a compact design of the exhaust system and a sufficiently large distance of the active sound damping device from the exhaust gas-carrying components can be achieved.

Preferably, the exhaust outlet ducts are exhaust tailpipes. The Abgasauslassleitungen thus lead directly into an environment of the exhaust system. In this case, exhaust valves can optionally be provided in the exhaust gas outlet lines in order to optionally close the exhaust gas outlet lines. The exhaust gas inlet pipe may have a substantially oval cross section at an exhaust gas outlet side end. By means of such a shaped cross-section, a compact construction of the exhaust system can be achieved.

Furthermore, the object is achieved by a motor vehicle having an exhaust system according to the invention. Such a motor vehicle is also simple in construction due to the simply constructed exhaust system. In addition, such a motor vehicle emits relatively little sound via its exhaust system to its surroundings. The invention will be explained below with reference to various embodiments, which are shown in the accompanying drawings. Show it:

FIG. 1 shows schematically a motor vehicle according to the invention with an exhaust system according to the invention according to a first embodiment, FIG. 2 shows the exhaust system according to the invention from FIG. 1,

FIG. 3 shows a section of the exhaust system according to the invention from FIG. 2, part of which is shown as transparent,

FIG. 4 schematically shows a detail of the exhaust system according to the invention from FIGS. 1 to 3, and FIG. 5 shows schematically an exhaust system according to the invention according to a second embodiment.

1 shows a motor vehicle 10 with an exhaust system 12 according to a first embodiment, which is coupled to an internal combustion engine 14 having three cylinders arranged in series. As can also be seen in particular in FIG. 2, the exhaust system 12 comprises a singular exhaust gas inlet line 16 and two exhaust gas outlet lines 18 connected thereto in an exhaust-gas-conducting manner, which are tailpipes in the illustrated embodiment.

In addition, the exhaust system 12 has an active sound damping device 20 which is sound conductively connected to the two Abgasauslassleitungen 18.

In this case, an active sound damping device known from the prior art is used as active sound damping device 20, which comprises a loudspeaker and by means of which it can generate sound that is in antiphase to the sound carried by the exhaust gas flow. For this purpose, the active sound damping device 20 is coupled to the exhaust gas outlet lines 18 via a sound line 22 and a sound coupling line 24.

In other words, the active sound damping device 20 is connected via the sound conductor 22 sound conducting to the sound injection path 24. In turn, the sound input line 24 is connected in a sound conducting manner to the exhaust gas outlet lines 18.

Furthermore, the exhaust system 12 has a passive muffler 26 with a muffler housing 28. In the first embodiment, the exhaust gas inlet line 16 is connected via the passive muffler 26 with the exhaust gas outlet lines 18 in an exhaust gas-conducting manner.

In Figure 3, an upper side of the muffler housing 28 is shown transparent, so that its interior is visible. In this case, the exhaust gas inlet line 16 and both exhaust gas outlet lines 18 extend in sections within the muffler housing 28.

More specifically, a portion of the exhaust gas inlet pipe 16 facing away from the engine 14, that is, the exhaust gas outlet side thereof, extends inside the muffler housing 28. The exhaust gas outlet side end may have a substantially oval cross section.

The cross section is regularly selected in this context so that both a good damping performance of the passive muffler 26 and a compact construction of the exhaust system 12 are achieved overall. As far as the exhaust gas outlet lines 18 are concerned, the sections facing the internal combustion engine 14 or the exhaust gas inlet line 16 run inside the silencer housing 28.

The two exhaust gas outlet lines 18 also form a T connection 32 with an exhaust gas intermediate line 30. Thus, both exhaust gas exhaust lines 18 are connected in an exhaust gas-conducting manner to the exhaust gas intermediate line 30.

The T-joint 32 is completely within the muffler housing

28th

The exhaust gas intermediate line 30 is also connected via the inner volume of the passive muffler 26 exhaust-conducting with the exhaust gas inlet line 16. In the first embodiment, the two exhaust gas outlet pipes 18 are formed by opposite portions of a common exhaust gas outlet pipe 34.

As already mentioned, the active sound damping device 20 is sound conductively connected to the exhaust gas outlet conduits 18 via the sound transmission line 24, in this case also with the exhaust gas outlet pipe 34.

In this case, the sound transmission line 24 has a larger diameter than the exhaust gas outlet lines 18 and engages on the outside the exhaust gas inlet side ends of the exhaust gas outlet lines 18 (see in particular FIG. 4). Presently, the sound transmission line 24 also surrounds the exhaust gas outlet pipe 34.

At the same time, the sound transmission line 24 extends essentially concentrically with the exhaust gas outlet lines 18, which are indeed formed by a common exhaust gas outlet pipe 34. The sound feed-in line 24 runs partly inside the silencer housing 28 and partly outside (see FIG. 4).

In order to enable an interaction of the antiphase sound generated by the active silencing unit 20 with the exhaust gas flow conducted into the exhaust gas outlet conduits 18, both exhaust gas exhaust conduits 18 have a perforated section 36.

To clarify that the two perforated sections 36 may or may not be the same, they differ in FIG. 4 in terms of the number of openings corresponding to the perforated section 36 and the arrangement of the openings. In this case, the perforated sections 36 are arranged in that region of the exhaust gas outlet lines 18 which is encompassed by the sound injection rail 24.

Further, the perforated portions 36 are placed on opposite sides of the exhaust gas conduit 30. In this case, the exhaust gas intermediate line 30 passes through a wall of the sound transmission line 24. Thus, the T connection 32 lies within the sound transmission line 24.

The sound conduit 22 extends completely outside the muffler housing 28.

In summary, therefore, outgoing from the engine 14 exhaust gas flows through the exhaust gas inlet pipe 16 into the muffler housing 28 of the passive muffler 26. From there it passes through the exhaust gas line 30, which is coupled to the two Abgasauslassleitungen 18 via the T-connection 32 in the two Abgasauslassleitungen 18. These direct the exhaust gas to the environment.

In the sense of damping the sound carried by the exhaust gas, in the active sound damping device 20, antiphase sound, which is often referred to as anti-noise, is generated. From there, the out-of-phase sound is conducted via the sound conductor 22 into the sound input line 24. It thus arrives in an annular space which is formed by the sound coupling line 24 and the respective exhaust gas inlet-side ends of the exhaust gas outlet lines 18. From this, the sound can escape via the openings of the perforated sections 36 into the interior of the exhaust gas outlet lines 18, where it interacts with the sound carried by the exhaust gas to dampen it.

The second embodiment of the exhaust system 12 shown in Figure 5 comes in contrast to the first embodiment without the passive muffler 26.

This variant can be selected when the exhaust system 12 is to be designed to save space.

This variant can also be used when the active sound damping device 20 is designed such that it can provide sufficient damping of the sound carried by the exhaust without the aid of a passive silencer. In addition, in the second embodiment, no exhaust gas passage 30 is used, so that the exhaust gas inlet pipe 16 communicates with the exhaust gas outlet pipes 18 forming the T-junction 32. The exhaust gas thus flows directly from the exhaust gas inlet line 16 into the exhaust gas outlet lines 18.

The path of the antiphase sound generated by the active sound damping device 20 and its superposition with the sound carried by the exhaust gas takes place in the same way as in the first embodiment. Reference is therefore made to the above statements.

Again, the perforated portions 36 are designed differently. This serves to clarify that they can be the same, but do not have to be.

Claims

claims

1 . Exhaust system (12) for an internal combustion engine (14) of a motor vehicle (10), with a singular exhaust gas inlet line (16), two Abgasauslassend with the exhaust gas inlet line (16) connected Abgasauslassleitungen (18) and an active Schalldämpfungseinrichtung (20), the sound conducting with two Abgasauslassleitungen (18) is connected.

2. Exhaust system (12) according to claim 1, characterized in that the exhaust gas inlet line (16) via a passive muffler (26) is exhaust-conductively connected to the Abgasauslassleitungen (18).

3. Exhaust system (12) according to claim 2, characterized in that the exhaust gas inlet line (16) and / or at least one of the exhaust gas outlet pipes (18), preferably both exhaust gas outlet pipes (18), in sections within a silencer housing (28) of the passive silencer (26). runs.

4. Exhaust system (12) according to any one of the preceding claims, characterized in that the two Abgasauslassleitungen (18) with the exhaust gas inlet line (16) or an exhaust gas line (30) form a T-connection (32) or a Y-connection, wherein the Exhaust gas line (30) is exhaust-conductively connected to both Abgasauslassleitungen (18) and the exhaust gas inlet line (16).

5. Exhaust system (12) according to any one of the preceding claims, characterized in that the two Abgasauslassleitungen (18) are formed by opposite portions of a common exhaust outlet pipe (34).

6. Exhaust system (12) according to any one of the preceding claims, characterized in that the active sound damping device (20) via a Schalleinkoppelleitung (24) is conductively connected to the Abgasauslassleitungen (18), wherein the Schalleinkoppelleitung (24) the exhaust gas inlet side ends of the exhaust gas outlet ( 18) on the outside and substantially concentric with the exhaust gas inlet side ends of the exhaust gas outlet lines (18).

7. exhaust system (12) according to one of the preceding claims and in particular according to claim 6 and claim 2, characterized in that the acoustic coupling line (24) runs at least partially within a silencer housing (28) of the passive silencer (26).

8. Exhaust system (12) according to any one of claims 6 and 7 and claim 4, characterized in that the exhaust gas intermediate line (30) or the exhaust gas inlet line (16) engages through a wall of the sound coupling line (24).

9. Exhaust system (12) according to any one of claims 6 to 8, characterized in that at least one of the Abgasauslassleitungen (18), preferably both Abgasauslassleitungen (18), in the area encompassed by the Schalleinkkopelleitung (24) comprises a perforated portion (36).

Exhaust system (12) according to claim 9 and claim 4, characterized in that both exhaust gas outlet ducts (18) comprise perforated sections (36) and the perforated sections (36) on opposite sides of the exhaust gas duct (30) or on opposite sides of the exhaust gas inlet duct (30). 16) are arranged.

1 1. Exhaust system (12) according to any one of claims 6 to 10, characterized in that the active sound damping device (20) via a sound line (22) is conductively connected in sound to the Schalleinkoppelleitung (24).

12. Exhaust system (12) according to claim 1 1 and claim 2, characterized in that the sound conduit (22) outside a muffler housing (28) of the passive muffler (26).

13. Exhaust system (12) according to any one of the preceding claims, characterized in that the Abgasauslassleitungen (18) are exhaust tailpipes.

14. Exhaust system (12) according to one of the preceding claims, characterized in that the exhaust gas inlet line (16) has a substantially oval cross-section at an end on the exhaust gas outlet end.

15. Motor vehicle (10) with an exhaust system (12) according to one of the preceding claims.