Gas flow and sound control valve for exhaust gas system

Abstract

Gas flow and sound control valve for an exhaust system of an internal combustion engine comprising a housing including an inlet, a first outlet, and a second outlet, and a valve member arranged within the housing for forming a first conduit connecting the inlet to the first outlet and/or a second conduit from the inlet to the second outlet, wherein the valve member can be moved relative to the housing between a first predetermined position in which the valve member closes the second conduit and a second predetermined position in which the valve member closes the first conduit, whereby the valve member is rotatable around a valve axis aligned parallel, in particular coaxial, to a centerline of the inlet.

Claims

1. A gas flow and sound control valve for an exhaust system of an internal combustion engine, the gas flow and sound control valve comprising: a Y-shaped housing including an inlet, a first outlet, and a second outlet, and a valve member arranged within the Y-shaped housing for forming a first conduit connecting the inlet to the first outlet and a second conduit from the inlet to the second outlet, wherein the valve member is configured to be moved relative to the Y-shaped housing between a first predetermined position in which the valve member closes the second conduit and a second predetermined position in which the valve member closes the first conduit, wherein the valve member comprises a spoon-shaped section for guiding exhaust gas from the inlet through the first conduit and/or the second conduit, wherein the spoon-shaped section defines an inner surface which, in the first predetermined position or the second predetermined position, merges with an inner conduit surface of a respective open conduit to define a boundary for an exhaust gas flow path resembling that of a bent pipe, wherein the valve member is rotatable around a valve axis aligned parallel to a centerline of the inlet, wherein the valve member is rotatably mounted to the Y-shaped housing with a central bearing arranged in the Y-shaped housing between the first outlet and the second outlet, wherein the valve member includes a shaft section aligned coaxially with the valve axis and extending through the central bearing and through the Y-shaped housing, wherein the valve member includes a wedge-shaped transition section arranged between the spoon-shaped section and the shaft section, and wherein the wedge-shaped transition section extends, in the first or second predetermined position, radially from an upstream tip of the spoon-shaped section into the respective open conduit and having a transition surface shaped corresponding to that of the respective open conduit and connecting the inner conduit surface of the respective open conduit to the inside surface.

2. The gas flow and sound control valve according to claim 1, wherein the spoon-shaped section is dimensioned such that it covers the second conduit in the first predetermined position and such that it covers the first conduit in the second predetermined position.

3. The gas flow and sound control valve according to claim 2, wherein the spoon-shaped section extends in a circumferential direction around the valve axis for at least 170?, and at most 220? along an axial extension along the valve axis of more than 3 cm.

4. The gas flow and sound control valve according to claim 2, wherein an inside surface of the spoon-shaped section defines a curved pipe-like flow path for the exhaust gas defining a radius of curvature, and wherein the spoon-shaped section is formed such that it defines an approximately constant cross section of the flow path in the first and second predetermined positions.

5. The gas flow and sound control valve according to claim 4, wherein centerlines of the outlets are arranged with an angular offset between 10? and 120? relative to the centerline of the inlet or the valve axis, wherein the Y-shaped housing defines a first radius of curvature spanning from the inlet to the first outlet and a second radius of curvature spanning from the inlet to the second outlet, and wherein in the first or second predetermined position the radius of curvature of the valve member corresponds to the respective first or second radius of curvature.

6. The gas flow and sound control valve according to claim 2, wherein an inner surface which, in the first or second predetermined position, merges with an inner conduit surface of the respective open first or second conduit to define a boundary for the exhaust gas flow path resembling that of a bent pipe, comprising exactly one bend and/or being formed free of obstacles within the respective open first or second conduit.

7. The gas flow and sound control valve according to claim 6, wherein the path of exhaust gas flowing from the inlet along the valve member to the first or second outlet through the respective conduit defines an essentially constant cross sectional area, and wherein an inlet funnel is arranged upstream of the inlet for guiding the path from another cross section to the cross sectional area of the inlet.

8. The gas flow and sound control valve according to claim 6, wherein a gap is defined in a direction radial relative to the valve axis between a radially outer surface of the spoon section and the Y-shaped housing at least partially along an axial extension of the spoon section.

9. The gas flow and sound control valve according to claim 1, wherein the valve member is rotatably mounted to the Y-shaped housing with an upstream bearing at the inlet, and wherein the valve member includes a ring section coaxially surrounding the valve axis and engaging the upstream bearing.

10. The gas flow and sound control valve according to claim 1, wherein the wedge-shaped transition section defines a shoulder wider than the shaft section and engaging the central bearing.

11. The gas flow and sound control valve according to claim 1, further comprising an actuator for manipulating the valve member, wherein the actuator is configured to arrange the valve member in at least one intermediate position between the first and second predetermined positions such that the valve member is positioned for guiding an exhaust gas flow and sound from the inlet to the first outlet and the second outlet while partially covering the first conduit and the second conduit.

12. The gas flow and sound control valve according to claim 9, wherein an upstream end of the valve member and the inlet are concentrically, aligned and/or have identical inner diameters corresponding to one another.

13. The gas flow and sound control valve according to claim 6, wherein the path of exhaust gas flowing from the inlet along the valve member to the first or second outlet through the respective conduit defines an essentially constant cross sectional area, and wherein an inlet funnel is arranged upstream of the inlet for guiding the path from an elliptical cross section to the cross sectional area of the inlet.

14. The gas flow and sound control valve according to claim 1, wherein the valve member is rotatably mounted to the Y-shaped housing with an upstream bearing that comprises a sliding bushing, at the inlet, and wherein the valve member includes a ring section coaxially surrounding the valve axis and engaging the upstream bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further embodiments, features and technical aspects are described in the subclaims. Further details of the preferred embodiments of the invention are shown in the enclosed Figures.

(2) FIG. 1a a frontal view of a gas flow and sound control valve according to one embodiment;

(3) FIG. 1b a cross-sectional view along the sectional line B-B of the valve according to FIG. 1a;

(4) FIG. 1c a cross-sectional view along the sectional line C-C of the valve shown in FIG. 1a;

(5) FIG. 1d a perspective cross-sectional view of the valve shown in FIG. 1a along the line B-B;

(6) FIG. 2 a perspective view of the valve member of the gas flow and sound control valve as shown in FIGS. 1a through 1d;

(7) FIG. 3a a top view onto a gas flow and sound control valve according to one embodiment;

(8) FIG. 3b a cross-sectional view of the valve shown in FIG. 3a along the line B-B;

(9) FIG. 3c a cross-sectional view along the line C-C of the valve shown in FIG. 3a;

(10) FIG. 3d a cross-sectional view along the line D-D of the valve shown in FIG. 3a;

(11) FIG. 4 a schematic illustration of an exhaust gas system including a gas flow and sound control valve;

(12) FIG. 5 another embodiment of an exhaust gas system including two gas flow and sound control valves;

(13) FIG. 6 another embodiment of an exhaust gas system including a gas flow and sound control valve; and

(14) FIG. 7 a schematic view of a section of a gas flow and sound control valve including a main tract and an impasse side tract including a gas flow and sound control valve.

DETAILED DESCRIPTION

(15) In the following description of preferred embodiments of the invention in accordance with the Figures, the same or similar reference numerals are used to designate the same or similar components.

(16) A gas flow and sound control valve is generally designated with reference numeral 1. For ease of reading, the term valve shall be used in the description of the embodiments shown in the Figures instead of the term gas flow and sound control valve to designate the same.

(17) The reference numerals 100, 200, 300 and 400 designate different exhaust gas system sections. It shall be understood that the architectures shown in the different Figures can be realized individually or in any combination. For example, one of the two tracts upstream from the valves shown in FIGS. 5 and 6 may each include an exhaust gas system as shown in FIGS. 4 and/or 7. Similarly, each of the four tracts downstream of the valves shown in FIGS. 5 and 6 may include one or both of the systems shown in FIGS. 4 and 7. Furthermore, it is conceivable that the system shown in FIG. 4 may include in one or both tracts downstream of the valve a system as shown in FIG. 7. Alternatively or additionally, the system shown in FIG. 7 can be arranged upstream of the valve of the embodiment shown in FIG. 4 or downstream of the unification junction of the embodiment shown in FIG. 4.

(18) It is a general concept realized in the exhaust gas flow and sound control valve 1 as shown in FIGS. 1a through 1d and 3a through 3d that exhaust gas may be led from one inlet to one outlet or another one outlet of said valve, while providing a throughflow area that resembles that of a bent tube having a (almost) constant, cylindrical cross-section. This is described in detail particularly with respect to FIGS. 3a through 3d below. Such an aerodynamically optimized shape devoid of undercuts and of pockets allows the exhaust gas to stream from the inlet to a first or to a second outlet nearly without loss of power and without impairing the exhaust system's sound emissions, thereby leading to improved sound quality and engine efficiency.

(19) The gas flow and sound control valve 1 includes as its main constituents a housing 3 and a valve member 7 arranged within the housing 3. The housing 3 may be designed approximately having a Y-shape. The housing 3 includes an inlet 5, a first outlet 10 and a second outlet 20. The valve member 7 is arranged within the housing 3 so as to form a first conduit 11 connecting the inlet 5 to the first outlet 10. Alternatively, the valve member 7 may be arranged within the housing 3 to form a second conduit 21 connecting the inlet 5 to the second outlet 20 in a second predetermined position. FIGS. 1a through 1d show the gas flow and sound control valve 1 with its valve member 7 in this predetermined second position. As can easily be conceived, the first predetermined position in which the valve member 7 forms a conduit 11 connecting the inlet 5 to the first outlet 10 would be mirror-symmetrically to the second predetermined position illustrated in the drawing 1A through 1D, which is not shown in detail.

(20) In the first predetermined position the valve member 7 closes the second conduit 21. In a second predetermined position, the valve member 7 closes the first conduit 11. It shall be clear that the valve may be designed in a way that leaves a small gap 35 in the radial direction between the valve member 7 and the housing 3 so that the valve member 7 may not seal the respective closed first or second conduit 11, 21 in an air-tight manner.

(21) The valve member 7, as shown in detail in FIG. 2, is rotatable about a valve axis A.sub.V. The valve member 7 comprises a spoon-shaped section, which might also be called a three-dimensionally curved section 71. The three-dimensionally curved section 71 of the valve member 7 forms an inner surface 75 shaped in a convex manner relative to the valve axis A.sub.V. The three-dimensionally curved section 71 of the valve member 7 is radially offset relative to the valve axis A.sub.V.

(22) The upstream end of the spoon-shaped section 71 may define a generally circular cross-section coaxial with respect to the valve axis A.sub.V. The downstream tip of the spoon-shaped section may be arranged on the valve axis or in close proximity thereto. This design of the valve member 7 permits a rotation of the valve member 7 about its axis A.sub.V within the tubular housing 3 and allows for an undisturbed flow of exhaust gas in the axial direction along the valve member 7.

(23) The valve member 7 is arranged in the housing 3 such that the valve axis A.sub.V is aligned parallel to (and may even be aligned coaxially to) a centerline A.sub.5 at the inlet 5 of the housing 3. When the inlet 5 as shown in the Figures has a circular cross-section, the centerline A.sub.5 may be defined by leading through the circle center.

(24) As shown in FIGS. 1a through 1d and 3a through 3d, the spoon-shaped section 71 of the valve member 7 is dimensioned to cover most or all of the respective second or first conduit 21 or 11 in a predefined first or second position. In the circumferential direction relative to the valve axis A.sub.V, the spoon-shaped section 71 extends around the valve axis such that it may completely cover one conduit and completely leave another conduit open. The circumferential extension ? of the spoon shaped section may be approximately 180?, for example 185??5?. In the example shown in the Figures, in which the housing has two outlets 10 and 20 to form a first conduit 11 or a second conduit 21, and in which the centerline A.sub.5 of the inlet 5, the centerline A.sub.10 of the first outlet 10 and the centerline A.sub.20 of the second outlet 20 are arranged in one single plane, the spoon-shaped section 71 may be designed to extend for approximately 180? around the valve axis A.sub.V.

(25) The extension of the spoon-shaped section 71 of the valve member 7 along the axial direction of the centerline A.sub.5 of the inlet 5 and the valve axis A.sub.V shall be designed to selectively cover one of the conduits 11 or 21. In a preferred embodiment, the extension of the spoon-shaped section 71 along the axial extension may be more than 3 cm and less than 10 cm. The spoon-shaped section 71 or three-dimensionally curved section is curved around the axis A.sub.V of the valve member and it is also curved in the axial extension along the valve axis A.sub.V. The spoon-shaped section 71 may display a partial bell shape, in particular the shape of an axially divided rotated parabola, rotated hyperbola or other rotated curve.

(26) In the Figures, the valve 1 is designed with a first outlet 10 and a second outlet 20 having the same shape and diameter. The inlet 5 shown in the Figures has the same size and shape as the first and second outlets 10 and 20. The first outlet 10 and the second outlet 20 may be of different size and/or shape and (not shown in detail). The inlet 5 and the outlets 10 and 20 may be of different sizes and/or shapes (not shown in detail). The number of outlets may differ from two.

(27) The inside surface 75 of the valve member 7 along its spoon-shaped section 71 defines a continuously curved-pipe-like flow path for the exhaust gas. The inside surface 75 may define a radius of curvature that is variable or, preferably, constant. The radius of curvature R.sub.7 is preferably designed in relation to the housing 3 such that its radius of curvature R.sub.7 arcs around a center of curvature equal or at least approximately equal to the center of curvature of which a curved centerline that arcs from the inlet 5 to either the first outlet 10 or the second outlet 20 arcs (cf. FIG. 1b).

(28) The outlets 10 and 20 define centerlines A.sub.10, A.sub.20 which may be defined by lines through the centers of a possibly circular cross-section of the outlets 10, 20. The centerlines A.sub.10 and A.sub.20 are arranged with an angular offset ?.sub.2 relative to the centerline A.sub.5 of the inlet. As shown in the Figures, the angular offset may be 45?. The angular offset ?.sub.1 of the first outlet 10 may be the same or different in comparison to the angular offset of the centerline A.sub.20 of the second outlet 20. The housing 3 defines a radius of curvature R.sub.10 or R.sub.20 spanning from the inlet 5 to the first outlet 10 and to the second outlet, respectively. In the first predefined position, the radius of curvature R.sub.7 of the valve member corresponds to the first radius of curvature R.sub.10. In the second predefined position, the radius of R.sub.7 of the valve member corresponds to the second radius of curvature R.sub.20. Thereby, in the first as well as in the second predefined positions, the exhaust gas streaming from the inlet 5 to the respective first outlet 10 or second outlet 20 may be guided along a constant radius of curvature to avoid vortices.

(29) The valve is designed so that in the first and second predefined positions, the exhaust gas flow resembles that of a bent pipe having exactly one bend and preferably being formed free of any obstacles.

(30) The exhaust gas flowing through the inlet 5 from the valve unit 7 to one of the first or the second outlets 10 or 20 flows along an essentially constant cross-sectional flow area Q in the Figures, particularly FIGS. 3a to 3d. This constant cross-sectional flow area Q is circular, as indicated with dashed lines in FIGS. 3b through 3d. Coming from the combustion engine, the exhaust gas enters to the housing 3 and the valve 7 at the upstream inlet 5 as shown for example in FIG. 3b. The exhaust gas is then guided by the curved shape of the housing 3 in conjunction with the valve member 7, in particular the spoon-shaped section 71. FIG. 3c shows a cross-section along the curved flow path of the exhaust gas through the valve 1 at a central part of the spoon-shaped section 71. As can be seen from FIG. 3c and indicated in dotted line, unlike in prior art valves, the cross-sectional area through which the exhaust gas flows along the valve member 7 remains essentially circular and preferably changes neither in size nor in shape with respect to the cross-sectional area at the inlet sides of the valve.

(31) FIG. 3d shows the cross-sectional area through which the exhaust gas flows at the second outlet 20, which is also circular and of the same throughflow-area as the two previous cross-sections. It shall be clear that the illustrations are schematic and not precisely of the same scale.

(32) The valve member may be rotatably mounted to the housing 3 with one or more bearings. One radial bearing 31 of the valve member 7 may be a sliding bushing 32 and the upstream end thereof 7 close to the inlet 5. For engaging the sliding bushing 32, the valve member 7 may include a ring section 73 that may surround the valve axis A.sub.V completely circumferentially. The valve member 7 may be mounted to the housing 3 with a central axial bearing 37. The axial bearing 37 may be arranged in the housing 3 between its outlets 10 and 20. The valve member 7 may include a shaft section 77 aligned coaxially with the valve axis A.sub.V. The shaft section 77 of the valve member 7 may extend through the central bearing 37 and through the housing 3. The shaft section 77 may be connected directly or via a transmission to an actuator (not shown in further detail) for turning the valve member 7 within the housing 3.

(33) The valve member 7 may further include a wedge-shaped transition section 76 arranged between the spoon-shaped section 71 and the shaft section 77. Such a transition section 76 may extend circumferentially around the axis A.sub.V to form an umbrella-like cover for the shaft section 77 to guard the axial bearing 37 from exhaust gas and/or to realize a cover to protect the exhaust gas from pockets in the vicinity of the axial bearing 37. The transition section 76 defines a shoulder 78 wider than the shaft section 77 engaging the central bearing 37. The transition section extends, as shown for example in FIG. 3b, 3c or 1b, from the spoon-shaped section 71 into the respective open conduit 11 or 21. A transition surface 79 of the transition section 76 may be designed to correspond to that of the respective open conduit 11 or 21 to connect a conduit surface 15 or 25 to the inside surface 75 of the spoon-shaped section 71.

(34) In addition to the first predetermined position and the second predetermined position, the valve member 7 may be situated within the housing 3 to be arranged in one or more intermediate positions between the first and second predefined position. In an intermediate position, the valve member 7 guides the exhaust gas flow and sound from the inlet 5 to both the first outlet 10 and to the second outlet 20. In the intermediate positions, the valve member may partially cover the first conduit 11 and/or the second conduit 21. By partially opening the conduits 11 and 21, the valve member 7 may allow exhaust gas to flow partially through the first conduit 11 and partially through the second conduit 21. The ratio of exhaust gas flow through the first outlet 10 relative to the exhaust gas flow through the inlet 5 depends on the rotational distance of the current intermediate position relative to the first predefined position. For example, in the first predetermined position, the valve member 7 would turn 0? from the first predetermined position, thereby leaving the first conduit 11 entirely open and guiding 100% of the exhaust gas from the inlet 5 to the first outlet 10. Conversely, in the second predetermined position the valve number as shown in the Figures would be rotated 180? away from the first predetermined position to completely close the first conduit 11 so that 100% of the exhaust gas would flow from the inlet 5 to the second outlet 20. 0% of the exhaust gas would flow from the inlet 5 to the first outlet 10. As described above, a small gap 35 may be provided between the valve member 7 and the housing 3 which may cause slight deviations from 100% or 0% throughflow. These slight deviations can usually be considered as insignificant and for a matter of the subject-matter of this patent application, the terms completely open and completely closed shall be understood to relate to a valve 1 in which a small gap 35 may be present.

(35) It has been shown that the ratio of flow from the inlet through the second conduit 21 to the second outlet 20 can be estimated to be proportional to the rotational distance of the valve 7 from the first predetermined position.

(36) Referring particularly to FIGS. 1b and 1c, the valve member 7 and in particular its ring section 73 may be arranged concentrically or may be even coaxially to the inlet 5. The upstream end of the valve member 7, as may be realized by the ring section 73 can have an identical inner diameter D.sub.7 corresponding to the inner diameter D.sub.5 of the inlet 5. This avoids any change in the cross-section through which the exhaust gas flows.

(37) The valve member 7 may consist of one integral member forming the spoon-shaped section 71 as well as the shaft 77 section and/or a ring section 73 for engaging an upstream bearing. The transition 76 section and/or the shoulder 78 may also be part of the integral one-piece valve member 7. An integral one-piece valve member may be manufactured in a 3D-printing process.

(38) FIG. 4 shows a first embodiment of en exhaust gas system 100 comprising an exhaust gas flow and a sound control valve 1. The exhaust gas flow c from the engine enters the exhaust gas system 100 at an upstream point of entry. After flowing through the exhaust gas system 100, a flow c leaves the exhaust gas system. Upstream and/or downstream of the exhaust gas system 100, further components may be arranged (not shown in further detail), for example one or more junctions for dividing or joining partial streams of exhaust gas, for example from a bank of cylinders, exhaust gas cleaning devices, such as catalyzers, one or more mufflers, etc. Downstream of the exhaust gas system 100 shown in FIG. 4, at least one outlet to the atmosphere is provided.

(39) Within the exhaust gas system 100, the incoming flow c of exhaust gas can be directed from one central inlet to either a right exhaust tract 13, a left exhaust tract 23 or partially through both the right exhaust tract 13 and the left exhaust tract 23. The guidance of the incoming exhaust gas stream c into the left and/or right exhaust tract 13, 23 is performed by the valve 1. The valve 1 may redirect the incoming flow c completely or in part into a stream c.sub.11 through the first conduit 11 of the valve 1 into the right exhaust tract 13. The valve 1 may redirect the incoming stream c of exhaust gas completely or in part into a stream c.sub.21 through the left conduit 21 into the left exhaust gas tract 23. As described above, the ratio of flow through the first and/or second conduit 11, 21 and consequently through the right or left exhaust tract 13, 23 may be controlled by the positioning of the valve member 7 within the housing 3 of the valve 1. It shall be clear that the terms left and right are used in conjunction with the illustrations for ease of understanding. As the valve 1 and the exhaust gas system 100 may be designed essentially mirror-symmetrical, so that the terms left and right may be used interchangeably. For the sake of ease of understanding, the terms right and left shall be understood as being interchangeable with the terms first and second as used in the claims. It shall be clear that the first and second conduit, tract, opening, etc. refer to distinct components of one valve or system. In other words, the use of the terms first and second imply the presence of at least two or more components as described.

(40) In the embodiment shown in FIG. 4, the right exhaust tract 13 is provided with an acoustic element 41. An acoustic element may be a resonator, an expansion chamber, a Helmholtz resonator, a muffler, an absorption muffler, or the like. Generally, an acoustic element 41, 43, 45 or 47 shall be understood to be any component of the exhaust gas system to modify, particularly amplify and/or attenuate the sound emissions from the internal combustion engine. The acoustic element may be designed to modify acoustic emissions within the first frequency band differently than sound emissions in a different, second frequency band. For example, an acoustic element may be designed to amplify sound emissions in a first frequency band and to attenuate sound emissions in a second frequency band.

(41) In the embodiment of an exhaust system 100 shown in FIG. 4, the left exhaust tract 23 consists of a pipe that is not provided with an acoustic element. It shall be clear that the second or left exhaust tract 23 may alternatively also be provided with an acoustic element (not shown).

(42) Downstream of the valve 1 which divides the incoming flow c into the first flow c.sub.11 through the first conduit 13 and into a second flow c.sub.21 through the second tract 23, a unification junction 50 is arranged where the first flow c.sub.11 and the second flow c.sub.21 are rejoined to the joined flow c in the exhaust system outlet tract 51. In the exhaust system outlet tract 51, an additional common acoustic element may be arranged (not shown in detail). The left and right tracts 13, 23 in conjunction with the unification junction 50 may be designed to form an acoustic element by designing the pipe of the first tract 13 to differ in length from the pipe of the second tract 23 between the valve 1 and the junction 50. The difference in length of the first tract 13 and the second tract 23 may be designed in correspondence with predefined frequencies of sound emission from the internal combustion engine in order to achieve negative and/or positive interference effects to modify the sound. If the first and second tracts 13 and 23 in conjunction with the junction 50 are designed to form an acoustic element, the individual tracts 13 and 23 may or may not be provided with additional acoustic elements.

(43) The exhaust gas system 200 shown in FIG. 5 receives two different incoming streams a, b. Preferably, the first stream a of exhaust gas comes exclusively from a first group of cylinders and the second stream b comes exclusively from a second group of cylinders of an internal combustion engine. In this regard, reference is made to the applicant's patent application EP 3 141 720 A1, particularly paragraphs [0002], [0007], [0008], [0026], [0043], [0044] and [0108], which are incorporated by reference in their entirety into the present application. The exhaust system 200 comprises a first exhaust gas flow and sound control valve 1a for the first incoming flow a, and a second valve 1b for the second stream b. Each of the valves 1a and 1b have a respective second outlet 20 leading to a respective bypass line 23a, 23b to discharge a flow a.sub.21, b.sub.21, possibly through an exhaust gas processing component or an acoustic element (not shown in further detail) to the atmosphere, with or preferably without mixing the bypass exhaust stream a.sub.21, b.sub.23 with exhaust gas from the respective incoming other stream b or a.

(44) Each of the first and the second valve 1.sub.a, 1.sub.b has a respective first outlet 10 connected to a respective first tract 13a, 13b, both of which tracts 13a, 13b lead to a singular common acoustic element 43. In the common acoustic element 43, acoustic emissions travelling with both of the incoming streams a and b may be modified. The common acoustic element 43 may be selected from the group of acoustic elements described above. Furthermore, the common acoustic element 43, may be realized as a common exhaust gas cleaning and/or silencing device as described in EP 3 118 429 A1, which is incorporated by reference in its entirety, wherein it shall be clear that a valve in accordance with the present invention shall be used upstream of the common exhaust gas cleaning and/or silencing device instead of the shut-off devices (reference numerals 43, 45 of EP 3 118 429 A1).

(45) The common acoustic element 43 has one or more outlet conduits 44a, 44b for guiding one or more possibly mixed streams ab, ba of exhaust gas directly or indirectly towards the atmosphere.

(46) In the embodiment of an exhaust gas system 200 illustrated in FIG. 5, the first and second valves 1a, 1b may be controlled identically, exclusively differently or independently. The guidance and/or division of the incoming stream a, b of exhaust gas into a first stream a.sub.11, b.sub.11 and/or a second stream a.sub.21, b.sub.21, respectively. Each valve 1a, 1b may be controlled by positioning the valve member 7 within the housing 3 of the valve as described above. Only one valve 1a or 1b, or both valves 1a and 1b may be designed to guide exhaust gas exclusively through the respective second conduit 21 to the bypass line 23a, 23b. Only one valve 1a or 1b or both valves 1a and 1b may be controlled to guide incoming exhaust gas a and/or b exclusively through their respective first conduits 11 to the common acoustic element 43. Only one valve 1a or 1b or both valves 1a and 1b may be controlled to guide incoming exhaust gas a and/or b so that it is divided into a respective first stream a.sub.11, and/or b.sub.11 and into a respective second stream a.sub.21 and/or b.sub.21. The respective first and second valves 1a and 1b can be controlled dependent on an engine setting, a performance setting and/or a desired sound output setting to guide exhaust gas from the internal combustion engine through the exhaust gas system for a desired modification of the acoustic emission, engine performance and/or cleaning performance.

(47) A further embodiment of an exhaust system 300 is shown in FIG. 6. The exhaust system 300 of FIG. 6 differs from exhaust system 200 shown in FIG. 5 in that the outlet conduits 44a and 44b are arranged to guide exhaust gas from the common acoustic element 43 to be joined with the exhaust gas flowing through the bypass tracts 23a and 23b. The right exhaust bypass line 23 and the right outlet conduit 44a are joined in a junction 50a Where an exhaust gas stream a.sub.21 may be joined with an exhaust gas stream exiting from the common acoustic element 43 to realize a mixed outlet stream ab. The design with the left tract portion may be essentially mirror-symmetrically so that a stream b.sub.21 to the second bypass line 23 is joined with exhaust gas stream coming from the common acoustic element 43 through the left outlet conduit 44b in the left junction 50b to realize another mixed exhaust gas stream ba.

(48) If a junction 50, 50a, 50b as described with respect to the embodiments of exhaust systems 100 or 300 of FIG. 4 or FIG. 6 is used, acoustic modifications may be achieved even if one of the lines upstream of the junctions 50, 50a or 50b is not supplied with an incoming stream by using it as an echo chamber or resonance chamber.

(49) FIG. 7 shows another embodiment of an exhaust gas system 400. The exhaust gas system 400 may be a subassembly within a larger exhaust gas system, for example an exhaust gas system 100, 200 or 300 as described above. The exhaust gas system 400 comprises a main line 55 receiving a stream d of exhaust gas directly or indirectly from an engine. The main line 55 discharges a stream of exhaust gas d directly or indirectly towards the atmosphere. A main line 55 can be understood to be a right or left exhaust tract 13, 13a, 13b, 23, 23a and/or 23b as described above. Alternatively or additionally, the main line 55 can be understood as a line upstream of a valve 1, 1a and/or 1b and/or a bypass line 23a and/or 23b, and/or an outlet conduit 44a and/or 44b, and/or a common exit line 54, 54a and/or 54b.

(50) In the exhaust gas system 400 shown in FIG. 7, an impasse side tract 5 is connected to the main tract 55. Exhaust gas that enters the impasse side tract 5 from the main tract 55 cannot exit to the atmosphere directly from the impasse side tract 5 but must re-enter the main tract 55 before being able to exit directly or indirectly to the atmosphere. In the exhaust gas system 400, an exhaust gas flow and sound control valve 1 is arranged within the impasse side tract 5. Each of the outlets 10, 20 of the valve 10 is connected to one respective impasse acoustic element 45, 47. The impasse acoustic elements 45, 47 may be selected from a group of impasse acoustic elements as described above. Preferably, the first impasse acoustic element 45 and the second impasse acoustic element 47 realize different acoustic modifications. For example, the first impasse acoustic element 45 may be designed to amplify sound emission whereas the second impasse acoustic element 47 may be designed to attenuate sound emissions. Alternatively or additionally, the first impasse acoustic element 45 may be designed to amplify sound emission of a first frequency band whereas the second impasse acoustic element 47 is designed to amplify sound emissions to a second frequency band. Any exhaust gas that entered one of the impasse acoustic elements 45, 47 can exclusively vent to the atmosphere via the main line 55, preferably by reversing the exhaust gas flow from the respective impasse acoustic element 45, 47 through the above-mentioned valve 1. The valve 1 may be controlled to divide a stream of exhaust gas coming from the impasse side tract 5 into a first stream d.sub.11 and into a second stream d.sub.21. The control and possible settings of the valve 1 correspond to those described above.

(51) Features disclosed in the above description, the figures and the claims may be significant for the realization of the invention in its different embodiments individually as well as in any combination thereof.

LIST OF REFERENCE SIGNS

(52) 1, 1a, 1b control valve 3 housing 5 inlet 5a right exhaust tract 5b left exhaust tract 5 impasse side tract 7 valve member 8 actuator 10 first outlet 11 first conduit 13, 13a, 13b first tract 15, 25 conduit surface 20 second outlet 21 second conduit 23, 23a, 23b second tract 31 radial bearing 32 sliding bushing 35 gap 37 central axial bearing 41, 43, 45, 47 acoustic element 44a, 44b outlet conduit 50, 50a, 50b junction 51 outlet tract 54, 54a, 54b exit line 55 main line 71 spoon-shaped section 73 ring section 74 outer surface 75 inner surface 76 transition section 77 shaft section 78 shoulder 79 transition surface 100, 200, 300, 400 exhaust gas system ?.sub.1, ?.sub.2 angular offset ? circumferential extension A.sub.V valve axis A.sub.5, A.sub.10, A.sub.20 centerline a, b incoming flow a.sub.21, b.sub.21, a.sub.23, b.sub.23 discharge flow ab, ba, ab, ba mixed flow c, c, c.sub.11, c.sub.21 exhaust gas flow d, d.sub.11, d.sub.21 exhaust gas flow D.sub.5, D.sub.7 inner diameter Q flow area R.sub.7, R.sub.10, R.sub.20 radius of curvature