EP3061931B1 - Exhaust gas system for a combustion engine - Google Patents

Description

The present invention relates to an exhaust system for an internal combustion engine, which may be provided for example in a passenger car, a truck or a bicycle.

In combustion exhaust gases from exhaust system leading away from an internal combustion engine, one or more probes are often provided for detecting the composition of the combustion exhaust gases, for example in an upstream region thereof, which intervene in the exhaust gas flow volume of the exhaust gas routing system for interaction with the exhaust gases. In the downstream end region of an exhaust gas guide system, this is generally open to the outside, so that in principle there is the possibility that in this downstream end region of the exhaust gas guide system liquid such. B. water, penetrates. If the water reaches the area of the probes, they can be damaged. Since the output signals of such probes representing the exhaust gas composition are used for the control, for example, of an internal combustion engine in order to achieve the lowest possible pollutant emission, a functional failure or a malfunction in the region of the probes can have a corresponding impairment in the operation of an internal combustion engine or other system areas of a vehicle entail.

An exhaust system according to the preamble of claim 1 is known from US 2014/0161677 A1 known. In the case of this exhaust gas guidance system, one of the two exhaust gas guide tube regions is radially widened in the region of two adjoining exhaust gas guide tube regions. The other exhaust duct portion engages the radially expanded exhaust duct portion, so that a gap of a ring-like shape is formed between the two duct portions. About this space is formed in the interior of the Abgasführungsrohrbereiche exhaust gas flow volume to a space adjacent to the abutment region of the exhaust gas guide tube regions and filled with particulate material space. In order to prevent passage of the particulate material through the gap, in this abutment region, the exhaust gas guide tube regions are surrounded by a fiber mat.

From the EP 1 039 105 A2 an exhaust system for an internal combustion engine is known in which in the region of two nested tubes a condensate trap is formed. For this purpose, the axial end of the pipe inserted into the other pipe is tapered or partially flattened to form a gap between these two pipes, which has either the shape of a ring or the shape of a circle segment.

It is the object of the present invention to provide an exhaust gas routing system for an internal combustion engine, in particular a vehicle, which prevents the penetration of liquid in a simple, stable and compact structure.

According to the invention, this object is achieved by an exhaust gas routing system for an internal combustion engine according to claim 1. This includes an upstream first exhaust duct portion, a downstream second exhaust duct portion adjoining the first exhaust duct portion in a transition region in an exhaust gas flow direction, one of an exhaust flow volume in the first exhaust duct portion and / or second exhaust duct region to a liquid collection volume open Flüssigkeitsableitkanalbereich in the transition region.

In the case of the exhaust-gas guidance system constructed according to the invention, where two exhaust-gas guide tube regions adjoin one another, it is ensured that liquid entering from the downstream end region of the exhaust-gas guidance system is discharged from the exhaust-gas flow volume via the liquid-discharging channel and absorbed in a fluid-collecting volume. The provision of the Flüssigkeitsableitkanalbereichs where two Abgasführungsrohrbereiche adjacent to each other, can be easily implemented in a compact design and avoids the incorporation of special channel arrangements in individual components of an exhaust system.

In the exhaust gas routing system according to the invention, it is further provided that the liquid discharge passage region comprises a gap formed between the first exhaust guide tube region and the second exhaust guide tube region. Such a gap can be provided in a simple manner, for example, by a jump in the transverse dimension of the adjoining exhaust duct sections and requires no additional structural measures.

On the one hand to be able to connect the two exhaust guide tube regions, and on the other hand to produce the space for the liquid outlet engages in the transition region, a downstream end portion of the first exhaust guide tube portion in an upstream end portion of the second exhaust guide tube portion, and the gap is in a peripheral region between an outer surface of the first exhaust duct portion and an inner surface of the second exhaust duct portion formed.

The dip in the transversal dimension in the transitional region between the two exhaust guide tube portions for creating the clearance for the liquid discharge passage portion is provided according to the invention by expanding the second exhaust guide tube portion upstream toward its upstream end portion in at least one direction transverse to the exhaust gas flow direction. This extension, for example with respect to a circular basic cross-sectional geometry, is provided in that the second exhaust-gas guide tube region has in its upstream end region a flattened, round peripheral contour, preferably oval or elliptical.

In order to provide the liquid collecting volume in association with the transitional region in the exhaust gas guidance system constructed according to the invention, proposed that the transition region is arranged in a housing which provides the liquid collection volume.

To provide a stable assembly, it is proposed that the housing has an inlet opening, wherein the first exhaust gas guide tube region is guided through the inlet opening into the interior of the housing, and / or has an outlet opening, wherein the second exhaust gas guide tube region out through the outlet opening from the interior of the housing is. In particular, it may be provided that the first exhaust gas guide tube region comprises a first tube section extending inside the housing, providing the downstream end region of the first exhaust guide tube region, firmly connected to the housing in the region of the inlet opening, and / or the second exhaust guide tube region has a inside tube Housing extending, the upstream end portion of the second exhaust guide tube area providing, with the housing in the region of the outlet opening firmly connected second pipe section comprises.

The housing may be constructed with the first pipe section and the second pipe section as an assembly in the manner of a silencer or rear silencer. In order to realize the supply and discharge of exhaust gases to or from this assembly in a simple manner, it is proposed that the first exhaust duct portion preferably with the first pipe section in the Includes / or that the second exhaust duct portion comprises a fourth pipe section preferably connected to the second pipe section in the region of the outlet opening fourth pipe section.

In order not only to provide the functionality of a liquid collection volume with the housing, but also to be able to use this in particular for soundproofing, it is proposed that at least one plate-type sound insulation element be arranged in the interior of the housing.

In this case, the arrangement may be such that at least one sound-damping element surrounds the upstream end region of the second exhaust-gas guide tube region or / and is firmly connected to the upstream end region of the second exhaust-gas guide tube region and / or is fixedly connected to the housing in its outer peripheral region and / or comprises a first sound-insulating opening arrangement , In particular, the at least one soundproofing element can subdivide the interior of the housing into two regions which are in communication with one another via the first soundproofing opening arrangement, so that nevertheless a large internal volume region of the housing is available as liquid collection volume.

The sound-damping functionality can be further improved in the exhaust-gas routing system according to the invention in that the second exhaust-gas guide tube region has a second sound-damping opening arrangement downstream of the transitional region in its region running inside the housing.

In order to make the structure as simple as possible in the area of the housing, but nevertheless to create the possibility to lead the two exhaust duct sections in this or to couple to this, it is proposed that the housing at least a part of, preferably the whole inlet opening and at least a portion of the outlet opening providing the first housing shell and a not through the first housing shell provided part of the inlet opening and a not provided by the first housing shell part of the outlet opening, with the first housing shell firmly connected second housing shell comprises.

Fig. 1

ein in einem Kraftfahrzeug einsetzbares Abgasführungssystem;

Fig. 2

einen stromabwärtigen Endbereich eines Abgasführungssystems mit einem nur teilweise dargestellten und ein Flüssigkeitssammelvolumen bereitstellenden Gehäuse;

Fig. 3

den in Fig. 2 dargestellten Bereich eines Abgasführungssystems, teilweise im Schnitt;

Fig. 4

in prinzipartiger Darstellung und betrachtet in Abgasströmungsrichtung, einen Übergangsbereich zwischen zwei Abgasführungsrohrbereichen.

The present invention will be described below in detail with reference to the accompanying drawings. It shows:

Fig. 1

a usable in a motor vehicle exhaust system;

Fig. 2

a downstream end portion of an exhaust gas guide system having a housing only partially illustrated and providing a fluid collection volume;

Fig. 3

the in Fig. 2 shown portion of an exhaust system, partially in section;

Fig. 4

in a schematic representation and considered in the exhaust gas flow direction, a transition region between two Abgasführungsrohrbereichen.

In Fig. 1 For example, an exhaust system 10 for an internal combustion engine is shown in a passenger car. The exhaust gas guide system 10 is formed in its upstream end portion 12 for receiving combustion exhaust gases from an internal combustion engine. In this upstream end region 12, probes 14, 16 are provided in the exhaust gas guidance system 10, which protrude into the gas flow flowing in the exhaust gas guidance system 10 and thus provide information about the composition of the combustion exhaust gases. This information can be used, for example, to control an internal combustion engine to minimize pollutant emissions. The combustion exhaust gases flow in a gas flow direction G through an exhaust pipe 17 from the upstream end portion 12 to a downstream end portion 18 of the exhaust guide system 10. At the downstream end portion 18, the exhaust gases leave the exhaust guide system 10 via two tail pipes 22 leading away from a muffler 20 in the illustrated embodiment , 24.

The following will be with reference to the Fig. 2 to 4 described technical measures by which it is ensured that in the region of the downstream end portion 18 in the exhaust gas guide system 10 entering liquid such. As water, is prevented from reaching towards the upstream end portion 12 and in particular the probes 14, 16 positioned there.

The FIGS. 2 and 3 show the downstream end portion 18 of the exhaust gas delivery system 20 with the muffler 20 positioned there. The muffler 20 includes a housing, generally designated 26, from which in FIG FIGS. 2 and 3 only a lower housing shell 28 is shown.

The exhaust gas routing system 10 includes an upstream first exhaust conduit portion 30 that leads into the interior 32 of the housing 26. Further, the exhaust gas guide system 10 includes a downstream second exhaust guide tube portion 34, which leads out of the interior 32 of the housing 26 and in which in the FIGS. 2 and 3 illustrated example with a single tail pipe 22 is formed. As the Fig. 3 1, the first exhaust guide tube portion 30 and the second exhaust guide tube portion 34 are in fluid communication so that the exhaust gases flowing through the exhaust guide system 10 can flow from the first exhaust guide tube portion 30 into the second exhaust guide tube portion 34 in the exhaust gas flow direction G.

In Fig. 3 It will be appreciated that a downstream end portion 36 of the first exhaust guide tube portion 30 engages an upstream end portion 40 of the second exhaust guide tube portion 34 in a transition region generally designated 38. For example, the first exhaust guide tube portion 30 and the second exhaust guide tube portion 34 may be formed in these end portions 38, 40 having a substantially cylindrical shape.

The first exhaust pipe section 30 includes a first pipe section 42 extending substantially inside the housing 32 and providing the downstream end section 36. The second exhaust pipe section 34 includes a second tubular portion 44 also extending substantially within the interior 32 of the housing 26, which provides the upstream end portion 40. In its end remote from the downstream end region 36, the first tube section 42 is inserted into an inlet opening 46 formed in the housing shell 28 and firmly and fluid-tightly connected in this area, for example, with a substantially cylindrical section 48 of the shell 28 enclosing the inlet opening 46, for example by welding , A third tube section 40 attributable to the first exhaust guide tube region 30 can be inserted, for example, in the region of the inlet opening 46 into the end of the first tube section 42 positioned there and thus be firmly and fluid-tightly connected, for example by welding.

The second pipe section 44 is fixedly connected in its region facing away from the upstream end portion 40 end in the region of a housing 26 formed in the outlet opening 52 with the housing, for example by welding. The FIGS. 2 and 3 clearly show that only part of this outlet opening 52 is formed in the lower housing shell 28 shown in the figures. The remaining part of the outlet opening is formed in the upper housing shell to be placed on the lower housing shell 28. Here, too, can be formed by these two housing shells together an outlet opening 52 surrounding, for example, cylindrical edge region, with which the second pipe section 44 may be fixed and fluid-tight manner, for example by welding. The two housing shells can be firmly and fluid-tight, for example by welding, in the region of flange-like edge regions 54 formed thereon. A, for example, in the region of the outlet opening 52 in the there positioned end of the second pipe section 44 inserted fourth pipe section 56 is fixedly connected to the second pipe section 44, for example by welding and provides the tailpipe 22 ready in the example shown, while the first pipe section 42, for example, an inlet pipe and For example, the second pipe section 44 may provide an exhaust pipe of the muffler 20.

In the region of the transitional region 38, the first tube section 42 and the second tube section 44 are dimensioned or shaped in their end regions 36, 40 such that a gap 58 positioned in a vehicle essentially in a lower region in the installed state results, essentially to the interior 32 of the housing 26 leading Flüssigkeitsableitkanal 60 forms. This intermediate space 58 can be provided, for example, by providing the first pipe section 42 in its downstream end region 36 with a substantially circular cross-sectional contour. The second pipe section 44 can be funnel-like expanded starting from a central region 62, which is also formed, for example, with a circular, essentially cylindrical cross-sectional geometry, and then flattened so that a flattened, for example approximately oval or elliptical, cross-sectional contour results in the upstream end region 40 of the second pipe section 44, which is expanded in at least one direction transverse to the gas flow direction G in comparison to the cross-sectional contour of the downstream end portion 36 of the first pipe section 42. Thus results in a peripheral region of the principle in the representation of Fig. 4 clearly visible, with approximately sickle-like shape formed gap 58 between an outer surface 64 of the first tube section 42 in the downstream end portion 36 and an inner surface 66 of the second tube section 44 in the upstream end portion 40. There, where the two end portions 36, 40 abut each other, ie in Fig. 4 in the upper part of the illustration, the two pipe sections 42, 44, for example, by welding or / and by press fitting firmly connected to each other.

The silencer 20 further comprises a plate-like sound insulation element 68 which surrounds the upstream end region 40, for example in the transition region 38 and is fixedly connected in this region to the second pipe section 44, which can be fixed with its outer peripheral region to an inner surface of the housing 26. The sound-damping element 68 divides the interior 32 of the housing 26 into two spatial areas 70, 72. Since a first sound-absorbing opening arrangement 74 comprising a multiplicity of holes or openings is formed in the sound-damping element 68, the two spatial areas 70, 72 are fundamentally in communication with one another. A second Acoustic opening arrangement 76 is formed in the central region 62 of the second pipe section 44, so that in principle the exhaust gas flow volume 78 formed in the region of the muffler 20 or in the area of the first exhaust pipe section 30 and the second exhaust pipe section 34 is open to the interior 32 of the housing 26. Primarily by sound reflection, the two sound insulation openings 74, 76 of the muffler 20 contribute to the sound attenuation.

By providing the substantially 58 Flüssigkeitsableitkanal 60 providing space 58 in the transition region 38 between the two Abgasführungsrohrbereichen 30, 34 for above the tail pipe 22 and the second Abgasführungsrohrbereich 34 penetrating liquid, such as water, the possibility is created before the penetration into the first Exhaust pipe section 30 to enter a provided in particular in the region of the lower housing shell 28 liquid collection volume 80. A portion of the water entering via the tailpipe 22, in particular when the inflow velocity is comparatively low, can also enter the liquid collection volume 80 via the second sound-insulating opening arrangement 76. However, especially in the event of gushing in of water, as may be the case, for example, when passing through liquid pools or water courses or the like, the water will substantially completely move across the second sound insulation opening arrangement 76 and can reach the liquid collection volume 80 via the intermediate space 58 , Thus, it is ensured that the exhaust gas delivery system 10 or a vehicle equipped therewith has the generally required wading capability, which ensures that even for a predetermined period of time with the internal combustion engine engine, the penetration of water into the exhaust system 10 to the upstream region 12, where the probes 14, 16 are positioned is prevented. By provided in the interior of the housing 26 liquid collection volume 80, a relatively large amount of liquid or water can be absorbed. In the combustion mode, this liquid will gradually evaporate due to the comparatively high temperature which the various components of the exhaust gas guide system 10 will have the exhaust gas flow direction G exhaust gas flow develops a suction pumping action for evaporating liquid and thus withdrawing the liquid vapor from the liquid collection volume 80. If necessary, in the area of the housing 26, also manually or automatically revealed drainage openings may be provided in order to discharge larger quantities of liquid accumulated therein.

By inventively provided possibility to divert into a discharge system liquid entering through a Flüssigkeitsableitkanalbereich in the transition region between two Abgasführungsrohrbereichen and store in a liquid collection volume, a simple, nevertheless feasible with a compact design possibility is created to protect further system areas of an exhaust system before entering liquid. The inventive structure of an exhaust system is therefore not only suitable for larger vehicles, such. As trucks or commercial vehicles, but can also be used in particular in passenger cars and two-wheeled application. The construction according to the invention of the exhaust gas guidance system does not impair the exhaust gas flow and thus does not lead to a higher back pressure and thus a loss of performance of a drive unit coupled to this exhaust gas routing system.

It should finally be pointed out that, of course, the exhaust gas guidance system according to the invention could be designed differently, in particular in the area of those components which provide or cooperate with the fluid discharge channel. Thus, of course, be provided in the interior of the liquid collection volume also providing housing for further contributing to the sound insulation measures. Such a housing providing the liquid collection volume could also be constructed exclusively for this purpose and without measures serving for soundproofing or without the positioning of components serving for sound insulation. Of course, as this, for example, the Fig. 1 shows the second Abgasführungsrohrbereich be constructed so that more than one tail pipe leads out of the housing.

Next, the exhaust gas guide system according to the invention could essentially be designed only as a silencer, so for example, the housing with the first pipe section and the second pipe section of the two Abgasführungsrohrbereiche include, to which pipe sections can then be added as separate assemblies more pipe sections.

Claims (10)

1. Exhaust gas guide system for an internal combustion engine, comprising:

   - an upstream, first exhaust gas guide pipe area (30),

   - a downstream, second exhaust gas guide pipe area (34) adjoining the first exhaust gas guide pipe area (30) in a transition area (38) in an exhaust gas flow direction (G),

   - a liquid drain channel area (60) in the transition area, which channel area is open from an exhaust gas flow volume (78) in the first exhaust gas guide pipe area (30) or/and in the second exhaust gas guide pipe area (34) to a liquid collection volume (80),
   wherein the second exhaust gas guide pipe area (34) is expanded upstream towards its upstream end area (40) with a cylindrical shape in at least one direction transversely to the exhaust gas flow direction (G) and wherein in the transition area (38) a circular downstream end area (36) of the first exhaust gas guide pipe area (30) with a cylindrical shape engages the upstream end area (40) of the second exhaust gas guide pipe area (34) with a cylindrical shape, wherein the liquid drain channel area (60) comprises an interspace (58) formed between the circular downstream end area (36) of the first exhaust gas guide pipe area (30) with a cylindrical shape and the upstream end area (40) of the second exhaust gas guide pipe area (34),
   wherein

   - the second exhaust gas guide pipe area (34) with its end region (40) with a cylindrical shape has a flattened round circumferential contour,

   - the intermediate space (58) is formed with a crescent shape in a circumferential region between an outer surface (64) of the circular downstream end region (36) adapted with a cylindrical shape of the exhaust gas guiding pipe area (30) and an inner surface (66) of the upstream end region (40) adapted with a cylindrical shape of the second exhaust gas guide pipe area (34), and in another circumferential area the circular downstream end region (36) of the first exhaust gas guide pipe area (30) and the upstream end region (40) adapted with a cylindrical shape of the second exhaust gas guide pipe area (34) abut at each other and are fixedly connected to each other by welding or/and press fit.
2. Exhaust gas guide system according to claim 1, characterized in that the second exhaust gas guide pipe area (34) has an oval or elliptical circumferential contour, in its upstream end area (40).
3. Exhaust gas guide system according to one of claims 1 or 2, characterized in that the transition area (38) is arranged in a housing (26) providing the liquid collection volume (80).
4. Exhaust gas guide system according to claim 3, characterized in that the housing (26) has an inlet opening (46), wherein the first exhaust gas guide pipe area (30) is led through the inlet opening (46) into the interior (32) of the housing (26), or/and an outlet opening (52), wherein the second exhaust gas guide pipe area (34) is led through the outlet opening (52) from the interior (32) of the housing (26).
5. Exhaust gas guide system according to claim 4, characterized in that the first exhaust gas guide pipe area (30) comprises a first pipe section (42), which extends in the interior (32) of the housing (26), provides the downstream end area (36) of the first exhaust gas guide pipe area (30) and is fixedly connected to the housing (26) in the area of the inlet opening (46), or/and that the second exhaust gas guide pipe area (34) comprises a second pipe section (44), which extends in the interior (32) of the housing (26), provides the upstream end area (40) of the second exhaust gas guide pipe area (34) and is fixedly connected to the housing (26) in the area of the outlet opening (52).
6. Exhaust gas guide system according to claim 5, characterized in that the first exhaust gas guide pipe area (30) comprises a third pipe section (50), which is fixedly connected to the first pipe section (42), preferably in the area of the inlet opening (46), or/and that the second exhaust gas guide pipe area (34) comprises a fourth pipe section (56) fixedly connected to the second pipe section (44) preferably in the area of the outlet opening (52).
7. Exhaust gas guide system according to one of the claims 3-6, characterized in that at least one plate-like sound absorption element (68) is arranged in the interior (32) of the housing (26).
8. Exhaust gas guide system according to claim 7, characterized in that at least one sound absorption element (68) surrounds the upstream end area (40) of the second exhaust gas guide pipe area (34) or/and is fixedly connected to the upstream end area (40) of the second exhaust gas guide pipe area (34) or/and is fixedly connected to the housing (26) in its outer circumferential area or/and comprises a first sound absorption opening arrangement (74).
9. Exhaust gas guide system according to one of the claims 3-8, characterized in that the second exhaust gas guide pipe area (34) has a second sound absorption opening arrangement (76) downstream of the transition area (38) in its area extending in the interior (32) of the housing (26).
10. Exhaust gas guide system according to claim 4, or one of claims 5-9, if referring back to claim 4, characterized in that the housing (26) comprises a first housing shell (28), which provides at least a part of and preferably the entire inlet opening (46) and at least a part of the outlet opening (52) and a second housing shell providing a part of the inlet opening (46), which part is not provided by the first housing shell (28) and providing a part of the outlet opening (52), which part is not provided by the first housing shell (28), which said second housing shell is fixedly connected to the first housing shell (28).

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