EP2617956B1 - Exhaust gas device for an internal combustion engine - Google Patents

Description

The present invention relates to an exhaust device for an internal combustion engine, preferably of a motor vehicle, and to a method for controlling acoustic actuators of such an exhaust device. In addition, the invention relates to a motor vehicle with such an exhaust device.

An exhaust device is primarily for the purpose of dissipating an exhaust gas generated by an internal combustion engine. For this purpose, the exhaust device to an exhaust line, through which the exhaust gas flows. The exhaust device can also be used for acoustic purposes. Thus, exhaust devices often have at least one muffler disposed in the exhaust line for manipulating and, in particular, filtering certain predetermined ranges of sound in the exhaust device and the sound generated by the exhaust device, respectively. Usually, the exhaust device upstream of the muffler with the internal combustion engine, in particular by means of one or more exhaust manifold, connectable. In a so-called dual-flow exhaust device, the exhaust line also has at least in a rear portion of two exhaust pipes, which are usually arranged downstream of the muffler. In order to generate certain acoustic effects, such as sounds that match the respective speed or load of the internal combustion engine, acoustic actuators can furthermore be provided, wherein the respective exhaust gas line can have at least one such actuator which is connected in a sound-transmitting manner to this exhaust gas line. Such an actuator is in particular an electromagnetic sound generator which forms a loudspeaker together with a membrane, wherein the sound generated by the loudspeaker can be transmitted to the respective exhaust pipe or to the exhaust gas. To realize the said acoustic effects in this case the interaction of the generated by the one exhaust pipe Sound with the sound produced by the other exhaust pipe, especially in the rear section, used.

The EP 0 840 285 A2 describes such an exhaust device in which the respective exhaust pipe an acoustic actuator is assigned, wherein the actuators are connected to generate acoustic effects with a control device.

From the EP 2 138 700 A2 For example, an exhaust system is known which has an acoustic intake actuator.

The disadvantage here is that always additional components or components are required to produce desired acoustic effects.

The present invention is concerned with the problem, for an exhaust device for an internal combustion engine, preferably a motor vehicle, and for a method for operating such an exhaust device, an improved or at least alternative embodiment, which is characterized in particular by an improved acoustic behavior and an improvement Variety of the generated with the exhaust device noise or acoustic effects is characterized.

This problem is solved by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea, in an exhaust device having at least in a rear portion of two exhaust pipes, each having at least one acoustic actuator, the respective exhaust pipe to form such or equip the exhaust device such the exhaust pipes generate and / or emit different or individual sound waves. Thus, it is possible, in particular, to achieve an increased diversity of the acoustic effects generated by the superposition of these sound waves, in particular in the far field or outside the exhaust gas device. Thus, in particular by constructive and destructive interference, desired acoustic noises can be generated or emphasized, while undesired noise is suppressed or reduced.

According to the invention, this is done by means of an uneven formation of the exhaust pipes or an uneven formation of an exhaust line of the exhaust device, in particular in the rear section. The sound waves emitted by the respective exhaust pipe are thus different, in particular even if the respective actuators are of the same design and / or generate the same acoustic signals. Such an unequal design of the exhaust pipes is realized, for example, when the exhaust pipes are formed asymmetrically or the actuators are arranged asymmetrically. An asymmetric design is e.g. given when the sound transmission of the acoustic signals generated by the actuators takes place at different locations of the respective exhaust pipes.

With the switching transmission of the acoustic signals generated by the actuators at different points of the respective exhaust pipes, it is in particular possible to achieve different emissions of sound waves of the respective exhaust pipe, even if the exhaust pipes, in particular in the rear section, are identical or identical.

The terms "rear" and "rear" relate here in particular in the sense of outflow on the flow direction of the exhaust gas flowing in the exhaust line or on the remote arrangement with respect to an internal combustion engine, with the exhaust gas line exhaust gas leading connectable. Accordingly, the exhaust line at least in this rear portion on two exhaust pipes, which are referred to as rear exhaust pipes, the rear exhaust pipes may be characterized in particular in that they are arranged downstream of an outlet of the exhaust device or have such an outlet. In the rear area of the exhaust system is thus configured double-ended.

In addition, the respective actuators can be designed or equipped such that they can simultaneously generate different acoustic signals. In this case, an embodiment is preferred in which the actuators of the different rear exhaust pipes are individually controllable or driven. The actuation of the actuators is preferably carried out with the aid of a control device. The control device is in this case designed such that it controls the actuators of the respective rear exhaust pipes individually, wherein the driving takes place with the aid of the output of a corresponding control signal or of control signals. Individually controllable means that the respective actuators can be controlled or controlled in such a way that they can generate the same acoustic signal and / or different acoustic signals. The individual control of the respective actuator, in particular in the far field, a variety of acoustic effects or noise can be generated, even if the respective actuators are the same design and / or if the rear exhaust pipes are the same. In particular, the rear exhaust pipes incl. The actuators may be formed as equal parts.

It is understood that both the rear exhaust pipes can be designed unequal and the actuators, in particular by means of the control device, are controllable such that they produce different acoustic signals at the same time.

Such exhaust device with the two rear exhaust pipes is commonly referred to as a double-flow exhaust device. Here, the exhaust gas line in a front portion, that is upstream of the rear portion, at least have a front exhaust pipe, which can connect the exhaust gas exhaust gas leading to the associated internal combustion engine. The at least one front exhaust pipe can be connected in any way with the rear exhaust pipes fluidly and / or sound transmitting. If the exhaust gas line has two front exhaust gas lines, then the connection to the rear exhaust gas lines can be realized, for example, by means of an X tube. If the exhaust gas system has a single front exhaust gas line, this connection can be realized, for example, by means of a Y tube. In the latter possibility, the front exhaust pipe thus divides at the junction of the Y-tube in the two rear exhaust pipes. Preferably takes place at the transition from the front portion in the rear portion, a uniform distribution of the exhaust gas in the rear exhaust pipes.

However, embodiments are also conceivable in which the exhaust system has two exhaust pipes throughout. Here, the "rear" exhaust pipes are designed continuously and can be connected in particular directly exhaust gas leading to the associated internal combustion engine.

In preferred embodiments, the exhaust device or the exhaust line to a component which couples the rear exhaust pipes sound transmitting each other. The component is thus able in particular to transmit the sound or the vibrations, in particular the airborne sound or the exhaust gas sound, to the rear exhaust pipes to the respective other rear exhaust pipe. In this case, mixing and / or treatment and / or manipulation of the exhaust gas by means of the component can also take place. The component is therefore particular the X-pipe and the Y-pipe or a mixing space or an exhaust gas treatment device for the exhaust gas. Embodiments are also conceivable in which the exhaust gas device has two or more such components or a combination thereof.

Expediently, the exhaust gas system has at least one silencer, which in particular serves to manipulate the sound of the exhaust gas flowing in the exhaust gas system. Preferably, the muffler is arranged between the rear exhaust pipes and the at least one front exhaust pipe. In other words, the exhaust system has, downstream of the muffler, the two rear exhaust pipes and, upstream of the muffler, the at least one front exhaust pipe. Accordingly, the muffler is such a component of the exhaust device, which realizes the scarf-transmitting coupling of the rear exhaust pipes. The exhaust gas generated by the internal combustion engine thus passes through the at least one front exhaust pipe and the at least one muffler in the rear exhaust pipes, wherein a uniform distribution of the exhaust gas usually takes place in the muffler.

The respective rear exhaust pipe has at least one such actuator, which acts in particular as an electromagnetic sound generator and can form a loudspeaker together with a membrane. The respective actuator is also connected sound-transmitting with the associated rear exhaust pipe, so that an acoustic signal generated by the actuator to the associated rear exhaust pipe or to the exhaust gas is transferable. It is therefore an airborne sound or fluidic connection between the actuator and the associated rear exhaust pipe. By superimposing the acoustic signal generated by the respective actuator with the sound waves of the exhaust gas flowing in the associated rear exhaust pipe or the exhaust gas sound waves, corresponding acoustic noises can thus be generated. In addition, superimpose the sound waves emitted by the respective rear exhaust pipe outside the exhaust device, that is, in particular in the far field, to a sound that is perceived by an outsider. The aim of the invention is to manipulate in particular these externally perceptible noises. The control device may have one or more control units. It is possible to control the respective actuator with a separate control unit. Also, two or more actuators may be controlled by the same control unit. The respective control unit can also be arranged outside the respective actuator, in particular in a control device housing of the control device, or in an actuator housing, in particular in a loudspeaker housing. The respective actuator expediently has a signal connection to the control device or to the associated control unit. The respective control units are preferably coupled to one another so that a synchronized control of the respective control units or actuators can take place.

In a preferred embodiment, at least one time-delaying element is provided, which is arranged in a connection path between at least one of the actuators and the control device. The time-delaying element serves the purpose of delaying the signal sent by the control device to the associated actuator. Consequently, the arrangement of the time-delaying element in the connection path means that the acoustic signal generated by this actuator is emitted in a time-shifted manner in comparison to the acoustic signal of another actuator, which is controlled by the control device with the same control signal. Hereby, these actuators generate different acoustic signals, which can be amplified or suppressed by a suitable choice of the time-delaying element predetermined or desired or unwanted noise. As an example of such a time-delaying element, reference is made in particular to a capacitor or to a capacitor circuit or a capacitor-like circuit. The time-delaying member can be connected to a be arranged anywhere in the connection path. This means that the time-delaying element can be arranged in / on the actuator, in the control device or in between. It is understood that in the connection path a plurality of such time-delaying members can be arranged, which are formed the same or different. It is also conceivable to arrange such time-delaying elements in a plurality of connection paths, wherein the respective time-delaying elements may be designed or equipped the same or different.

The control device can preferably change the control signal sent to the respective actuators depending on predetermined parameters or adapt them. Such parameters may be, for example, state variables of the internal combustion engine, for example a rotational speed and / or a load of the internal combustion engine and thermodynamic parameters of the internal combustion engine, for example the temperature. Also, the respective acoustic signal of acoustic conditions of the associated internal combustion engine or the exhaust device depend. For this purpose, in particular microphones may be provided which are arranged at suitable locations, for example at or in the vicinity of the internal combustion engine or the exhaust device. Suitably, these microphones have a connection to the control device. In addition, the control signals output at one or more of the actuators may depend on the acoustic signal from another or more other actuators. Accordingly, a query of the respective actuator can take place via said connection path or an additional connection, or a sound sensor, for example a microphone, can be assigned to the corresponding actuators. If a plurality of control units are provided, preferably at least two of them are coupled to one another so that a synchronized control of the respective control units or actuators can take place.

The transmission of the acoustic signal generated by the respective actuator to the associated rear exhaust pipe is preferably carried out via a coupling point of the associated rear exhaust pipe. In particular, the coupling point can be the connection point between the exhaust gas line and a sound conduit which is fluidically connected to the associated actuator. The use of such a sound conduit has the advantage that a thermal protection or a reduced thermal load of the actuator is given by the hot and aggressive exhaust gases by the distance created between the actuator and the associated rear exhaust pipe by means of the sound conduction. In addition, a volume is thereby present, which can serve to generate the acoustic signal of the associated actuator.

With the aid of a different arrangement of the coupling points of the respective rear exhaust pipe, an uneven formation of these exhaust pipes can be achieved. According to a preferred embodiment, the exhaust line is formed such that the distance between the coupling point of a rear exhaust pipe and the outlet of this rear exhaust pipe along this rear exhaust pipe is greater than the distance between the coupling point of the other rear exhaust pipe and the outlet of this rear exhaust pipe along this rear exhaust pipe. The outlet of the respective rear exhaust pipe is in this case in particular the point at which the exhaust gas exits from the respective rear exhaust pipe. The outlet is thus arranged downstream of the coupling point and can correspond to an end pipe of the exhaust device. As a result, the respective exhaust pipes emit time-shifted sound waves, so that acoustic effects or noises can be generated in the far field which can not be generated with identical emitted sound waves. Preferred embodiments are those in which these distances differ by at least 10 cm. This typically results in the beating of the emitted sound waves, with which said acoustic effects can be generated. In particular, in the sound-transmitting component having exhaust devices embodiments are preferred in which the distance between the coupling point of a rear exhaust pipe and the upstream component, in particular the muffler or the X-tube or the Y-tube, along this rear exhaust pipe is greater than the distance between the coupling point of the other rear exhaust pipe and the upstream component along this rear exhaust pipe. In general, the upstream of the coupling point of a rear exhaust pipe arranged component corresponds to the component which is arranged upstream of the coupling point of the other rear exhaust pipe. This means that the two rear exhaust pipes open into the same component upstream or are coupled to the same component. Alternatively, these distances may be between the respective coupling point and the first upstream impedance discontinuity, this impedance discontinuity usually being said component. Here, the knowledge is used that a different reaction to the component is achieved by the different distance of the respective coupling point to the component. This reaction or transfer function of the component to the respective coupling point and thus to the respective actuator leads to different superimpositions of this reaction with the acoustic signal generated by the respective actuator. As a result, the frequencies or amplitudes of the sound waves emitted by the respective rear exhaust pipe may be different, so that in particular in the far field, by the superposition of these emitted sound waves acoustic effects and noises are generated, which with identical emitted sound waves of the respective rear exhaust pipe not or difficult are realizing.

The sound waves emitted by the respective rear exhaust pipes preferably differ by a slight frequency shift. That is, a frequency difference between the two emitted sound waves is preferably only a few Hz. Here, the knowledge is used that it comes in the superposition of such waves to a so-called beating. By exploiting this beating effect, it is possible, for example, to produce asymmetric noises which are clearly audible in the low-frequency range. In other words, in the far field, a noise or acoustic effect can be generated, which is emitted directly neither from the actuators nor from the respective rear exhaust pipe. The said low-frequency and in particular asymmetric noises may produce, for example, a typical noise for an eight-cylinder internal combustion engine, although the exhaust device is connected to another internal combustion engine having fewer or more than eight cylinders.

Alternatively or additionally, the generation of different emitted sound waves of the respective rear exhaust pipe, as already mentioned, carried out by the different driving of the respective actuators, wherein the control, that is, the transmission of a corresponding control signal to the respective actuator by means of the control device. In the following, it is assumed for the sake of simplicity that the respective rear exhaust pipe has only a single associated actuator, but it is understood that the description given below can be extended analogously to embodiments in which the rear exhaust pipes and in each case have a plurality of actuators.

In a preferred embodiment, the control device controls the actuators in such a way that the acoustic signal generated by the actuator of the one rear exhaust pipe compared to that of the actuator of the other rear exhaust pipe generated acoustic signal has a frequency shift. This means that the acoustic signals of the respective actuators have different wavelengths. This frequency difference preferably corresponds to 5 Hz. In particular, one actuator generates an acoustic signal with a frequency of 100 Hz, while the acoustic signal of the other actuator has a frequency of 105 Hz. As a result, in particular, said beat effect can be generated or utilized and, in particular, a low-frequency noise can be generated.

Alternatively or additionally, the acoustic signals generated by the different actuators have different amplitudes. This means that the control device controls the actuators in such a way that the acoustic signal generated by the actuator of the one rear exhaust pipe has a different amplitude than the acoustic signal generated by the actuator of the other rear exhaust pipe, these amplitudes preferably being more than 2 dB differ.

In a further variant, the acoustic signals generated by the different actuators have a phase shift. Here, the phase shift can be variably controlled or constant. This means that the acoustic signals generated by both actuators are identical, but have a frequency-dependent time shift. Preferred embodiments are those in which the phase shift is at least 10 °.

Another possibility is given by the fact that the acoustic signals generated by the different actuators have a time shift. This means that the control device actuates the actuators in such a way that the acoustic signal generated by the actuator of one rear exhaust pipe is compared to the acoustic signal generated by the actuator of the other rear exhaust pipe has a time lag. The time shift between the two acoustic signals is in particular constant and greater than 0.05 ms. The time shift between the acoustic signals generated by the respective actuator results in different phase shifts of the acoustic signals as a function of the frequency of these acoustic signals. A similar effect can, as already mentioned, be achieved by the arrangement of the time-delaying element in the corresponding connection path.

Another possibility is that the acoustic signals generated by the actuators of the respective rear exhaust pipe have different frequency compositions. This can be achieved, for example, by the control device actuating the actuators in such a way that the acoustic signal generated by the actuator of one rear exhaust pipe has a different frequency composition compared with the acoustic signal generated by the actuator of the other rear exhaust pipe. This can be realized in particular by the superimposition of different frequency components.

It is understood that the frequency shift and / or the different amplitudes and / or the phase shift and / or the time shift and / or the frequency composition of the respective acoustic signals can also apply to the control signal sent to these actuators, in particular if the actuators are the same are formed.

It should also be noted that the reproduced here properties of the rear exhaust pipes and the associated actuators analogously to the at least one front exhaust pipe is transferable. Furthermore, the exhaust gas system or the exhaust gas device may have three or more rear exhaust gas lines, wherein at least two of the rear exhaust gas lines comprise such an associated actuator and are designed or equipped in accordance with the invention that they can simultaneously emit different sound waves without departing from the scope of this invention.

In an advantageous development of the solution according to the invention, such an exhaust device is part of a motor vehicle. The motor vehicle further comprises an internal combustion engine, which is fluidically connected to the at least one front exhaust pipe of the exhaust device. The fluidic connection between the internal combustion engine and the at least one front exhaust pipe is preferably ensured by means of or via an exhaust manifold, wherein the exhaust manifold may be part of the exhaust device. In this case, embodiments are preferred in which the exhaust device has two such front exhaust pipes, which are assigned to different areas of the internal combustion engine. This means that the internal combustion engine can be designed or equipped such that the exhaust gas produced by different cylinders or different groups of cylinders is discharged via the one front exhaust pipe or via the other front exhaust pipe.

In a preferred embodiment, the motor vehicle has an intake line, which supplies the internal combustion engine with air or supplies the air to the internal combustion engine. In addition, at least one acoustic Ansaugaktor is provided, which is connected sound transmitting with the intake manifold. The at least one intake actuator is preferably controlled by the control device, so that the acoustic signal generated by the intake actuator is controllable by the control device. Thus, the controller may tune the acoustic signals generated by the actuators of the rear exhaust conduits and the acoustic signal generated by the intake actuator and accordingly allow a greater variety of audible sounds. Suitably, the control device is designed or equipped so that they Control signals to the different actuators or Ansaugaktoren tune with each other or can match. Predetermined parameters or determined parameters and state variables can also play a role here. For example, one or more microphones or sound sensors may be provided which measure the noise at predetermined locations, in particular in the vicinity of the internal combustion engine or in a passenger compartment of the motor vehicle. In addition, the temperature, the speed and the load of the internal combustion engine can have an influence on the actuators controlled by the control device or on the corresponding control signals. For this purpose, in particular curves or characteristic maps can be provided, which are assigned to the operating points of the internal combustion engine or of the vehicle. This makes it possible to adapt the noise generated by the motor vehicle and in particular to the outside or in the vehicle, in particular in the passenger compartment, to specific predefined driving situations or operating points.

Alternatively or additionally, the motor vehicle may also have an acoustic inner actuator, which is arranged in the interior of the motor vehicle, in particular in the passenger compartment of the motor vehicle. With the help of this inner actuator, it is possible to manipulate in particular the sounds audible to a driver of the motor vehicle. For example, "sporty" and "dynamic" driving situations can be intensified or accompanied by appropriate sounds.

It should be noted that the unequal design of the rear exhaust pipes or the exhaust device in this area and the arrangements of the respective coupling points in particular also depend on the geometric conditions of the associated motor vehicle and the respective acoustic requirements. The same applies to the activation of the actuators, these Possibility by a more cost-effective implementation and greater variability allows a greater variety of producible acoustic effects.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Fig. 1 bis Fig. 4

eine stark vereinfachte, schaltplanartige Darstellung eines Kraftfahrzeugs, jeweils unterschiedlicher Ausführungsform

Fig. 5

eine vereinfachte Darstellung einer Abgasvorrichtung,

Fig. 6

eine stark vereinfachte Darstellung eines Kraftfahrzeugs.

Show, in each case schematically,

Fig. 1 to Fig. 4

a greatly simplified, schematic diagram of a motor vehicle, each different embodiment

Fig. 5

a simplified representation of an exhaust device,

Fig. 6

a greatly simplified representation of a motor vehicle.

Corresponding Fig. 1 to Fig. 3 For example, a motor vehicle 1 has an exhaust device 2 that serves to exhaust an exhaust gas generated by an internal combustion engine 3 of the motor vehicle 1. Refer to the names upstream or downstream in the following on the given in the exhaust device 3 flow direction of the exhaust gas, which is indicated by an arrow 10. The same applies to the terms "rear" and "front", wherein "rear" in the flow direction 10 is further away from the internal combustion engine 3 than "front". The exhaust gas device 2 is designed to be double-flowed at least in a rear section X and accordingly has two exhaust-gas-carrying exhaust gas lines 11 in the rear section X, which are referred to below as the rear exhaust gas lines 11. In the in the Fig. 1 to 3 In the examples shown, the rear exhaust pipes 11 are coupled to one another in a sound-transmitting manner by means of at least one component 4. Here, the component 4 is in Fig. 1 as a sound damper 4 'or as an arbitrary mixing chamber 4' and in Fig. 2 designed as X-tube 4 " Fig. 3 embodiment shown has two such components 4, wherein one of the components 4 as Y-tube 4 '"is designed, while the other component 4 is formed as a dam spring 4' and upstream of the Y-tube 4 '" is arranged.

The exhaust line 5 has upstream of the component 4, at least one front exhaust pipe 6, wherein the in Fig. 1 and Fig. 2 shown examples, two such front exhaust pipes 6, while the in Fig. 3 embodiment shown having such a front exhaust pipe 6. Accordingly, in the examples shown, the component 4 divides the exhaust line 5 into the rear section X and the front section Y. The respective front exhaust line 6 is connected to the internal combustion engine 3 in exhaust gas. This exhaust-carrying connection takes place via an exhaust manifold 7. The respective exhaust manifold 7 collects and concentrates the exhaust gas generated by a plurality of cylinders 8 of the internal combustion engine 3 and supplies them to the respective associated front exhaust pipe 6. The respective component 4 also ensures an equal distribution of the exhaust gas flowing from the at least one front exhaust pipe 6 into the rear exhaust pipes 11 Fig. 1 shown exhaust line 5 also has two exhaust-treatment units 9, for example Particle filter 9 and / or catalysts 9, which are each arranged upstream of the muffler 4 'in one of the front exhaust pipes 6.

This in Fig. 4 example shown has in contrast to those in the Fig. 1 to Fig. 3 embodiments shown no sound-transmitting component 4. Accordingly, the exhaust line 5 has two continuous exhaust gas conduits 11 which, for the sake of simplicity, will be referred to hereinafter as "rear" exhaust gas conduits 11, although they extend as far as the front section Y.

All shown exhaust devices 2 are thus formed as so-called twin-flow exhaust device 2 and thus have in the rear area X two rear exhaust pipes 11, which discharge the exhaust to the outside. The respective rear exhaust pipe 11 comprises an acoustic actuator 12, which may be formed or equipped, for example, as an electromagnetic actuator 12. The rear exhaust pipes 11 are the same except for the arrangement or connection of the respectively associated actuator 12. The respective actuator 12 forms, together with a membrane 13, a loudspeaker 14 which is arranged in a loudspeaker housing 15. The respective actuator 12 or loudspeaker 14 is connected to transmit sound, in particular airborne transmission, to the associated rear exhaust pipe 11. For this purpose, a sound conduit 16 is provided, which fluidly connects the respective actuator 12 or loudspeaker 14 with the associated rear exhaust pipe 11.

When in Fig. 4 In the example shown, the respective actuators 12 can in principle also be arranged in the front section Y of the exhaust gas line 5.

The fluidic connection between the actuator 12 and the associated rear exhaust pipe 11 by means of the sound conduit 16 is, as in the Fig. 5 shown, realized in that the speaker housing 15 has an opening 17, while the associated rear exhaust pipe 11 has a different opening or a coupling point 18, wherein the respective sound line 16 fluidly connects the opening 17 of the speaker housing 15 with the associated coupling point 18 of the rear exhaust pipe 11 ,

In order for the respective rear exhaust gas lines 11 to emit a different sound wave 19, the exhaust gas line 5, in particular in the area of the rear exhaust gas lines 11, is designed unequally. That is, the one rear exhaust pipe 11 is formed differently than the other rear exhaust pipe 11.

At the in Fig. 1 to Fig. 4 As shown, this is realized by extending in opposite directions sound lines 16 and positioned at different locations coupling points 18. The rear exhaust pipes 11 thus have an asymmetrical design relative to each other. The asymmetrical design of the rear exhaust pipes 11 and the different arrangement of the coupling points 18 lead in the in the Fig. 1 to Fig. 3 in particular to the fact that the coupling point 18 'of the one rear exhaust pipe 11' along this rear exhaust pipe 11 'has a greater distance 20' to the upstream component 4 than the distance 20 "between the coupling point 18" of the other rear exhaust pipe 11 " along this rear exhaust pipe 11 ". In addition, the coupling point 18 'in the Fig. 1 to Fig. 4 illustrated embodiments of a rear exhaust pipe 11 'along this rear exhaust pipe 11' at a smaller distance 20 '"to an outlet 21, in particular the tail pipe 21, this rear exhaust pipe 11', which is smaller than the distance 20""between the coupling point 18th "of the other rear exhaust pipe 11" to the outlet 21 of this rear exhaust pipe 11 ". It is immaterial which of the coupling points 18 of the one rear exhaust pipe 11 has a greater distance 20 to the muffler 4 and the associated outlet 21.

Due to the different arrangement of the coupling points 18 or by the asymmetrical design of the rear exhaust pipes 11 and their sound lines 16, it is possible to manipulate exhaust gas waves 22 originating from the internal combustion engine 3 so that the sound waves 19 emitted by the one rear exhaust pipe 11 are different That is, in particular, that the sound waves 19 emitting from the one rear exhaust pipe 11 may have a different frequency and / or amplitude than the sound waves 19 emitted from the other rear exhaust pipe 11 , like in the Fig. 5 shown by the fact that by the respective actuator 12 and speaker 14 generated acoustic signals 23 cooperate in different ways with the exhaust sound waves 22 and overlap with them. As in Fig. 5 shown schematically, this is partly due to the fact that the sound lines 18 and the actuators 12 and speakers 14 are arranged opposite or asymmetrical. Accordingly, when the acoustic signals 23 of the actuators 12 coincide with the exhaust-gas sound waves 22 in the region of the coupling points 18, different superimpositions or interferences occur. As a result, the resulting sound waves 24 'of one exhaust pipe 11 have a different characteristic, such as a different amplitude, than the resulting sound waves 24 "of the other rear exhaust pipe 11. Thus, those through the outlet 21 of a rear exhaust pipe 11 emitted sound waves 19 'characterized differently than the emitted through the outlet 21 of the other rear exhaust pipe 11 sound waves 19 ". In particular, these emitted sound waves 19, 19 "may have different frequencies and / or amplitudes and / or frequency compositions as well as a phase shift. that is, outside the exhaust device 2, noise generated due to the superposition of the emitted waves 19 is manipulated. This makes it possible to suppress unwanted noise or to produce desired sounds that correspond for example to a strong internal combustion engine or a sporty driving style.

The different distances 20 of the coupling points 18 with the respective rear exhaust pipes 11 additionally lead to a different feedback between the coupling point 18 and the component 4 or the associated outlet 21. These different feedbacks also have an influence on the resulting sound waves 24 and consequently on the emitted sound waves 19 and may, for example, lead to frequency overlays.

An alternative or additional possibility for generating different emitted sound waves 19 is in Fig. 1 shown. Here, a control device 25 is provided, which controls the actuators 12 of the rear exhaust pipes 11. This means that the control device 25 sends via a connection 26 to the respective actuator 12 a control signal to the actuators 12, which convert the actuators into the corresponding acoustic signals 23. In addition, a time-delaying element 28, in particular a capacitor 28, is arranged along a connection path 27 between the control device 25 and one of the actuators 12. The time-delaying element 28 delays the control signal sent to the associated actuator 12, so that the actuators 12 produce different acoustic signals 23 with a corresponding time shift, with identical control signals output by the control device 25, which have a phase shift depending on the frequency of the acoustic signals 23. Alternatively or additionally, the control device can control the respective actuator 12 in such a way that the acoustic signal 23 generated by the actuator 12 of the one rear exhaust pipe 11 is different compared to the acoustic signal 23 of the actuator 12 of the other rear exhaust pipe. In particular, the acoustic signals 23 may differ by a time shift, phase shift and different amplitudes and / or frequencies and / or frequency compositions.

It is also conceivable to arrange the control device 25 in the loudspeaker housing 15 of one of the speakers 14 in order to protect the control device 25 from thermal effects of the exhaust gas and to save space. It is also conceivable to equip the control device 25 with a plurality of control units, and to arrange the respective control unit in such an associated speaker housing 15. The control device 25 or the respective control units are in particular designed or equipped in such a way that they actuate the associated actuators 12 as a function of one another or in dependence on external parameters and / or predetermined parameters.

As in Fig. 6 shown, the actuators 12 of the rear exhaust pipes 11 with actuators 29 of a suction line 30 of the motor vehicle 1, which serves to supply air to the internal combustion engine 3 cooperate. The actuators 29 or intake actuators 29 assigned to the intake line 30 generate acoustic signals which interact with air waves of the intake line 30. In addition, the motor vehicle 1 has an inner actuator 31, for example, an inner loudspeaker 31, which is arranged in the interior of the motor vehicle 1, in particular in a passenger compartment 32 of the motor vehicle 1. By the interaction of the actuators 12 of the rear exhaust pipes 11 with the Ansaugaktor 29 and the inner actuator 38, an increased variety of inmates of the motor vehicle 1 and audible from the outside noise can be generated. *****

Claims (17)

1. Exhaust gas device (2) for an internal combustion engine (3), preferably of a motor vehicle (1), comprising an exhaust gas duct (5) which is formed to be a dual-branch exhaust gas duct at least in a rear portion (X), wherein

   - the dual-branch portion (X) comprises two exhaust gas lines (11),

   - the respective exhaust gas line (11) comprises at least one acoustic actuator (12) which is connected to said exhaust gas line (11) in a sound-transmitting manner,

   - the exhaust gas lines (11) have different designs.
2. Exhaust gas device according to claim 1, characterised in that a control apparatus (25) is provided and is designed to individually actuate the actuators (12) of the respective exhaust gas lines (11).
3. Exhaust gas device according to claim 2, characterised in that a time-lagging member (28), in particular a capacitor (28), is provided in a connection path (27) between at least one of the actuators (12) and the control apparatus (25).
4. Exhaust gas device according to any of claims 1 to 3, characterised in that the respective exhaust gas line (11) comprises a coupling point (18) at which sound is transmitted from the respective actuator (12) to the associated exhaust gas line (11).
5. Exhaust gas device according to claim 4, characterised in that the spacing (20) between the coupling point (18) in one of the exhaust gas lines (11) and an outlet (21) of said exhaust gas line (11) along said exhaust gas line (11) is at least 10 cm greater than the spacing (20) between the coupling point (18) in the other exhaust gas line (11) and the outlet (21) of said exhaust gas line (11) along said exhaust gas line (11).
6. Exhaust gas device according to any of claims 1 to 5, characterised in that the exhaust gas duct (5) comprises a component (4) which couples the exhaust gas lines (11) to one another in a sound-transmitting manner.
7. Exhaust gas device according to claim 6, characterised in that the spacing (20) between the coupling point (18) in one of the exhaust gas lines (11) and the component (4) along said rear exhaust gas line (11) is greater than the spacing (20) between the coupling point (18) in the other rear exhaust gas line (11) and the component (4) along said rear exhaust gas line (11).
8. Exhaust gas device according to either claim 6 or claim 7, characterised in that the component (4) is an exhaust silencer (4') or an X-pipe (4") or a Y-pipe (4"') or a combination thereof.
9. Method for controlling actuators (12) in an exhaust gas device (2) according to any of claims 2 to 8 by means of a control apparatus (25) connected to the respective actuator (12), wherein at least two of the actuators (12) are actuated individually by the control apparatus (25).
10. Method according to claim 9, characterised in that the control apparatus (25) actuates the actuators (12) in such a way that the acoustic signal (23) generated by the at least one actuator (12) of one of the exhaust gas lines (11) has a frequency shift compared with the acoustic signal (23) generated by the at least one actuator (12) of the other exhaust gas line (11), the frequency shift being, in particular, approximately 5 Hz.
11. Method according to either claim 9 or claim 10, characterised in that the control apparatus (25) actuates the actuators (12) in such a way that the acoustic signal (23) generated by the at least one actuator (12) of one of the exhaust gas lines (11) has an amplitude which is different from that of the acoustic signal (23) generated by the at least one actuator (12) of the other exhaust gas line (11).
12. Method according to any of claims 9 to 11, characterised in that the control apparatus (25) actuates the actuators (12) in such a way that the acoustic signal (23) generated by the at least one actuator (12) of one of the exhaust gas lines (11) has a phase shift compared with the acoustic signal (23) generated by the at least one actuator (12) of the other exhaust gas line (11).
13. Method according to any of claims 9 to 12, characterised in that the control apparatus (25) actuates the actuators (12) in such a way that the acoustic signal (23) generated by the at least one actuator (12) of one of the exhaust gas lines (11) has a time shift compared with the acoustic signal (23) generated by the at least one actuator (12) of the other exhaust gas line (11).
14. Method according to any of claims 9 to 13, characterised in that the control apparatus (25) actuates the actuators (12) in such a way that the acoustic signal (23) generated by the at least one actuator (12) of one of the exhaust gas lines (11) has a different frequency composition compared with the acoustic signal (23) generated by the at least one actuator (12) of the other exhaust gas line (11).
15. Motor vehicle (1) comprising an internal combustion engine (3) and an exhaust gas device (2), according to any of claims 1 to 8, which is connected to the internal combustion engine (3) such that it guides exhaust gas and which is controlled in particular using a method according to any of claims 9 to 14.
16. Motor vehicle according to claim 15, characterised in that the motor vehicle (1) comprises an intake duct (30) which is intended for supplying the internal combustion engine (3) with air and is connected to an associated acoustic intake actuator (29) in a sound-transmitting manner, the intake actuator (29) being controllable in particular with the aid of the control apparatus (25).
17. Motor vehicle according to either claim 15 or claim 16, characterised in that the motor vehicle (1) comprises at least one acoustic internal actuator (31) which is arranged inside the motor vehicle (1), in particular in a passenger compartment (32) of the motor vehicle (1), and can be controlled by the control apparatus (25).

Images