EP2607640A1 - Actuator assembly for active exhaust systems and method for operating the same - Google Patents

Abstract

The arrangement has a gas-conveying connection section (28b) connected with an exhaust line (22) of an exhaust system (21). A pressure equalization arrangement (29) comprises a recess (29a) and/or duct element for supplying fluid (F) into the gas-conveying connection section. The pressure equalization arrangement comprises a valve, a steering wheel, a controllable valve and/or a filter, where the steering wheel and/or controllable valve is adjustable in an electrical, hydraulic and/or pneumatic manner. Independent claims are also included for the following: (1) an active exhaust system (2) a method for operating an actuator arrangement.

Description

The invention relates to an actuator arrangement for active exhaust systems according to the preamble of patent claim 1, a method for operating the same and an active exhaust system according to the preamble of patent claim 8.

In known exhaust systems are usually passive mufflers are used, which are adapted to reduce combustion noise of a combustion engine connected to the exhaust system below a predefined level. In particular, in exhaust systems for motor vehicles in this regard are strict legal requirements for approval of the exhaust system.

In addition to the pure reduction of combustion noise, the muffler but also used to a sound design and this usually equipped with additional resonators or absorption mufflers and reflection mufflers.

Such exhaust systems include, for example, a pre-muffler (VSD), a center muffler (MSD) and a rear muffler (NSD) and can be single or double-flow, depending on the engine type. Double-flow exhaust systems can also have a cross-talk station.

In addition to the mufflers built-in electrical actuators are used in a so-called "active" exhaust systems to further influence combustion noise or to a further sound design. These actuators are usually arranged in the flow direction of the exhaust gas behind the last muffler and gas-conducting connected by means of a branch pipe with the exhaust system of the exhaust system.

Such an arrangement allows a targeted generation of defined sound waves. These can be fed via the branch pipe to the sound waves originating from the combustion in the engine, ie the combustion noise. In this way, the perceptible to a tailpipe of the exhaust system noise can be influenced by the actuator-generated sound waves.

A disadvantage proves to be as an actuator used for coming speaker, which is usually electrically operated and installed in a housing against an environment is completed. The loudspeaker of the actuator comprises electrical components and heat-sensitive magnets, which are specified up to a temperature of 100 ° C or even up to 150 ° C, depending on the component. When exposed to higher temperatures, the components are damaged or even unusable. These temperatures are thus well below an operating temperature of conventional exhaust systems, which can easily be several hundred degrees. To make matters worse, this means that there is less space required, which requires an immediate spatial proximity of the heat-sensitive actuator and the hot exhaust system.

To reduce these disadvantages, it is known, the actuator - as described - by means of a gas-conducting connecting pipe with the exhaust line of the To connect exhaust system and thus space the actuator spatially from this heat source. Illustratively, this means that the connecting pipe branches off from the exhaust gas line with a first end and is connected at its opposite second end to the actuator. By means of this arrangement, the physical principle of a stationary air column in the connecting pipe for sound transmission from the actuator is used in the exhaust system. At the same time due to the standing air column - at least in the ideal case - no air exchange with the flowing past in the connection area hot exhaust gas, so that it can be kept away from the actuator.

However, this ideal case can not be fully implemented in practice. Even with a stringency-optimized connection of the connecting pipe turbulences always occur at the exhaust gas line, which lead to the formation of a negative pressure region and to a gas exchange effected thereby with the actually standing air column. Even if this occurs only in an immediate mouth region of the connecting pipe in the exhaust system, the gas exchange still leads over a longer period of operation to a temperature increase in the region of the actuator, which can be damaged.

The thermal load of the actuator is supported by an additional heat conduction from the exhaust line to the connecting pipe and via this to the standing air column or the actuator, so that the actuator is exposed to an additional thermal load. This is particularly important with reduced or missing external cooling air due to a lack of vehicle flow, so for example when driving slowly or a stoppage of the vehicle after a full load or a slow ascent, of importance.

Another disadvantageous effect of the known arrangement is due to the fact that the described described in the mouth region negative pressure range via the connecting tube also provides for a negative pressure on the front side of the actuator facing the exhaust gas. Since a pressure prevailing at the same time on the rear side of the actuator remote therefrom is essentially unchanged and thus above the pressure on the front side, the resulting pressure difference results in a diaphragm of the actuator being deflected in the direction of the exhaust gas line. As a result, a control of the actuator and an efficiency of the actuator are adversely affected. In general, the actuator, which is usually designed as a loudspeaker, only reaches full efficiency if the pressure difference between the front and the back of the associated diaphragm is zero. Only then is the membrane in its non-active state in its original rest position and can be completely deflected in both directions of movement.

The above-described negative pressure region in the mouth region between the connecting pipe and the exhaust gas line is based, for example, on pressure losses, in particular a flow influencing of the exhaust gas flow through the mouth region, so that the formation of a significant negative pressure region can not be prevented, especially with high exhaust gas flows. For the purposes of this description, negative pressure is always to be understood as meaning a reduced static pressure at the respective point described relative to a barometric ambient pressure.

The object of the invention is therefore to provide an actuator arrangement which reduces or even eliminates the disadvantages described. In particular, in this context, a thermal load of the actuator is reduced and an efficiency of the actuator can be increased.

This object is achieved by means of an actuator arrangement with the features of patent claim 1 and an active exhaust system with the features of claim 9 and a method according to claim 12. Advantageous embodiments emerge from the respective dependent claims.

Accordingly, an actuator arrangement is provided for active exhaust systems for generating a sound signal with at least one actuator, wherein the actuator arrangement with at least one connecting section gas-conducting with at least one exhaust system of the exhaust system is connectable. The actuator assembly also includes a pressure equalization arrangement for supplying fluid into the connection portion.

Accordingly, the Aktoranordnung can be arranged by means of the connecting portion as a gas-carrying strand for providing an air column to the exhaust line, for example, as branched off from the exhaust line pipe string. A volume enclosed by the actuator arrangement, in particular in the region of the connection section, is designed to be gas-conducting and connectable to an exhaust-carrying volume of the exhaust gas system for exchanging fluid. Thus, sound waves generated by the actuator can be supplied to the exhaust gas line via the connecting section and superimposed on the combustion noises transmitted there.

The actuator arrangement described additionally allows by means of the supply of fluid into the connecting portion, that this can also be forwarded via the connecting portion in the exhaust system of the exhaust system. Thus, if, in a connected state in an opening region of the connection section, a negative pressure region is produced in the exhaust gas line as a result of an exhaust gas flow, a negative pressure also arises in the connection section or in the region of the actuator. By supplying the fluid into the connecting section, however, this resulting negative pressure can be reduced by means of the pressure compensation arrangement. The negative pressure area causes the fluid to be sucked into the connecting section and from there into the exhaust line.

As an additional effect, the supplied fluid - depending on a temperature of the fluid - provide ventilation and cooling of the actuator assembly in two ways. On the one hand, the supplied fluid prevents an inflow of hot exhaust gas from the exhaust gas line and presses it back in the direction of the exhaust gas line. On the other hand, it ensures a cooling flow when flowing through the actuator arrangement, in particular for a temperature reduction in the region of the connecting section, so that heat conduction via the connecting section to the actuator is reduced.

The actuator can thus be protected from high temperatures by hot exhaust gas and from heat conduction via the connecting section.

In other words, it is thus possible to selectively reduce a negative pressure at the actuator by supplying the fluid into the actuator arrangement and compensating or at least reducing a negative pressure. In this way, the described, acting on the actuator pressure difference between its front and the back can be reduced and thus the efficiency of the actuator can be increased. In addition, by a lower thermal load, a durability and a lifetime of the actuator is increased.

As also already shown, the actuator is intended to generate defined sound waves, which are transmitted via an air column arranged in the connecting section into the exhaust gas line. There, the sound waves superimpose the combustion noises of the internal combustion engine transported via the exhaust gas line with the exhaust gas.

In this way, the perceptible to a tailpipe of the exhaust system noise can be influenced by the actuator-generated sound waves such that in an in-phase design, for example, for the purpose of sound design, a gain or even a complete superposition of combustion noise is possible. Leave in the same way attenuate by means of an antiphase interpretation of the combustion noise of the engine accordingly. The damping is thus effected by so-called "anti-sound", ie by opposite-phase vibration superposition, and is particularly suitable for compliance with legally defined limits for noise emission as well as a reduction of disturbing resonance noise, such as a hum. For a reduction of these resonant noise so far resonators in the NSD have to be adapted consuming.

For this purpose, the actuator preferably comprises a loudspeaker, in particular an electrically operable loudspeaker. In principle, however, other controllable and / or controllable devices for generating defined sound waves can be used.

It proves to be particularly advantageous if the use of the pressure compensation arrangement is optionally used in combination with the described control or regulation of the actuator for generating sound or anti-sound. It is of particular importance that the actuator is not limited by an excessive pressure difference in its efficiency. This requirement can be achieved according to the invention by means of the pressure equalization arrangement. This is the only way to quickly and effectively generate appropriate anti-sound sound waves to dampen momentary combustion noises that are emitted to the environment via the exhaust system or the rear silencer.

In particular, the actuator arrangement described thus allows a combination with a controllable actuator, in contrast to previously used actuators, which are only controllable. The control is characterized in that the actuator can be operated in response to instantaneous combustion noise. It is thus made possible to provide defined sound waves by means of a corresponding control of the actuator, which corresponds to the instantaneous combustion noise for reduction by means of anti-sound are optimally adapted. Exemplary adaptation parameters are a frequency, an amplitude and / or a phase shift to the combustion noise.

For the anti-sound control of the actuator, the temperatures of the air column in the connecting portion between the actuator and the exhaust system are also important. These influence a sound transmission from the actuator to the exhaust gas, so that they must be taken into account, for example, to determine a signal propagation time or a wavelength. If the connecting section or the air column contained therein can be kept at a defined operating temperature or at least within a defined temperature interval due to the supply of the fluid, the costly adaptation measures can also be reduced and the anti-noise control can be adjusted accordingly. For example, the anti-noise control can be based on a correspondingly adapted temperature model.

It is likewise possible to provide temperature sensors and / or pressure sensors in the area of the actuator arrangement in order to be able to determine an instantaneous temperature and / or a momentary pressure of the air column and to adapt the anti-noise control.

According to one embodiment, the pressure compensation arrangement comprises at least one recess and / or at least one conduit element for supplying the fluid into the gas-carrying connection section of the actuator arrangement.

This means that the pressure compensation arrangement can comprise one or more recesses, which are provided, for example, in the form of bores or openings of any shape in the actuator arrangement and designed to allow a supply of the fluid through the at least one recess in the actuator arrangement. Additionally or alternatively one or more of the conduit elements may be provided. As a conduit element is in particular a guide channel for supplying the fluid to understand, for example in the form of a hose, a pipe or a channel. Further embodiments are shown below. Preferably, the pressure compensation arrangement is acoustically favorably designed and / or arranged acoustically favorable to reduce or even prevent additional noise due to the supplied fluid.

An embodiment as a hose, for example, allows the hose with a first end to fluidly connect to the actuator and / or the connecting portion and lead away an opposite second of the line member or the hose for supplying the fluid from the actuator assembly and spatially to place such that under other pollution or a dirt entry can be prevented together with the fluid.

Preferably, the supplied fluid is air, in particular ambient air. This means that, in particular, ambient air from the immediate vicinity of the actuator arrangement or, depending on the configuration of the line element, can be taken from a spaced area of the environment, such as a vehicle environment, and supplied to the actuator arrangement. In particular, the negative pressure occurring in the mouth region may in this case be configured for suction of the fluid for feeding into the actuator arrangement or the connecting section and forwarding into the exhaust gas line. Additional measures for supplying the fluid, in particular fans or pumps are not required, but still possible. For example, the actuator arrangement may comprise a fan for the controllable and / or controllable supply of fluid into the connection section. A throughput of the supplied fluid flow can thus be influenced.

It is understood that in addition to the fluids described in principle also other suitable gaseous or liquid substances can be used as a fluid. However, to simplify the description, the invention will be illustrated by the use of ambient air as the fluid.

According to a further embodiment, the pressure compensation arrangement comprises a valve, a controllable and / or controllable valve and / or a filter, wherein the controllable and / or controllable valve is designed to be electrically, hydraulically and / or pneumatically controllable.

Thus, the valve may be formed, for example switchable and thus allows a controlled opening or closing of the pressure compensation arrangement. The switching can be done, for example, mechanically, electrically, hydraulically or pneumatically. The use of the valve prevents a permanent opening of the actuator assembly to the environment, so that an outflow of exhaust gases can be prevented. In addition, it prevents possibly occurring flow noise of the fluid through the recess or the line element, at least in the closed state of the valve. It is understood that the pressure equalization port may include more than one valve. In addition, a plurality of actuator arrangements, for example in dual-flow exhaust systems, can be connected to one another such that only one common valve must be provided for the plurality of pressure compensation arrangements of the multiple actuator arrangements.

A closing of the valve can be provided, for example, if no pressure equalization is desired. If, on the other hand, a negative pressure in the actuator arrangement is to be reduced, then the valve can be opened. If the pressure compensation arrangement additionally has a filter, then the supplied fluid, for example the air supplied, can be filtered by means of the filter and thus the ingress of contaminants in the form of dirt or water can be prevented. According to an embodiment For example, the valve and the filter may be combined together to form a common component. For example, a mechanically switchable valve can also be designed to be actuatable by means of a bias voltage.

Accordingly, the valve can alternatively also be controllable and / or controllable, in particular electrically, hydraulically and / or pneumatically controllable. This offers the possibility to selectively control the valve in order to reduce a negative pressure at the actuator to a defined extent. In contrast to a merely switchable operation between a closed and an open position, a controller or control allows any number of intermediate positions or a stepless control. The control or regulation can be based, for example, on a temperature measurement, a temperature model, a rotational speed of a drive unit, its load state or other variables. Such a control by means of a control or regulation thus also makes it possible to select an opening point of the valve independently of a currently applied negative pressure in the connecting element or on the actuator. The control of the valve can also be done on the basis of predefined functions or via a map control. In this way, the described pressure difference applied to the actuator can be reduced by targeted compensation or targeted reduction of the negative pressure and as a result its efficiency can be increased.

Only, for example, can be used as a valve, a so-called electrical switching valve for switching between an open and closed operating state. If, on the other hand, a regulated valve is to be provided, then for example a pressure transducer can be used. All switchable and controllable valves can be switched or regulated directly or at least indirectly via a control unit. A corresponding control device is described below.

In addition, the pressure compensation arrangement may be associated with the actuator and / or the connecting portion. Accordingly, therefore, for example, the described recess and / or a first end of the conduit element may be arranged in the actuator, in the connecting portion or in both, in order to supply the fluid into the actuator arrangement in the respective region. The decisive factor here is merely that the region of the supply to the connecting portion and thus in the installed state is connected in a gas-conducting manner with the exhaust gas line, so that a pressure compensation in the region of the actuator can be effected.

Furthermore, the actuator may comprise an encapsulated housing or an encapsulated housing with at least one pressure equalization opening. In contrast to the described pressure equalization arrangement, the pressure equalization opening can be provided to provide a pressure equalization on a side of the actuator facing away from the hot exhaust gas, in particular a rear side of the loudspeaker diaphragm of the actuator facing away from the hot exhaust gas, and not provided for a supply of fluid in the direction of the connecting element. It is thus possible to achieve a balance between a pressure applied in the area of the rear side and a barometric ambient pressure of the vehicle, that is to say a static air pressure.

According to a further embodiment, the at least one line element at least in sections comprises a cooling channel for cooling the actuator arrangement. This means that the at least one line element can be designed to cool the actuator arrangement. For example, the line element may be arranged on an outer surface of the actuator arrangement for this purpose. Alternatively, the line element may be formed as a cooling channel in a wall of the actuator assembly. In particular, the line element can be provided as a cooling jacket or cooling capsule at least in the region of the actuator and / or the connecting portion.

Regardless of the specific embodiment, however, the line element is designed to receive fluid at its second end and to introduce it into the actuator arrangement along a line path. As described, the line course can be arranged correspondingly, that the fluid flowing through a cooling effect and can absorb heat energy from the actuator assembly in the fluid, which is forwarded to the exhaust line after being fed into the connecting portion.

For further thermal protection against heat or heat radiation acting from the outside, the actuator arrangement can be designed to be thermally insulated from an environment at least in sections. For this purpose, one or more heat shields or encapsulations for thermal shielding can be arranged as required, in particular in such a way that, when installed, they enable shielding or encapsulation with respect to the exhaust system of the exhaust system. The actuator can thus be thermally isolated from an environment and simultaneously cooled by the supply of fluid into the connection section, so that heat build-up in the area of the actuator or within the actuator arrangement is prevented.

It is further proposed an active exhaust system with an exhaust line and a gas-conducting connected to the exhaust line actuator assembly, wherein the actuator assembly is formed according to the given description.

In addition, a connection of the connecting portion of the actuator assembly may be configured, for example, with the exhaust gas line as a Y-shaped branch line. If several actuator arrangements are to be connected directly to an exhaust gas line, then the line branching must be adapted accordingly, for example, several Y-shaped line branches are arranged in series, or two Y-shaped line sections are integrated into a cross-shaped (X-shaped) line section. Furthermore, the branching be designed to connect an actuator with two or more exhaust strands accordingly.

According to a further embodiment, a geometry of the exhaust system is formed at least in the region of the line branch to form a flow-induced negative pressure for sucking fluid from the actuator assembly into the exhaust line, the line branch defining a connection between the connecting portion of the actuator assembly with the exhaust line. In particular, a suitable geometry may be provided for reinforcement of an already existing flow-induced negative pressure area in order to additionally increase the supply of the fluid. In this way, an increased cooling is effected in the region of the actuator or the connecting element.

In other words, a cooling ventilation of the actuator arrangement can thus be influenced and thus reinforced. Also in this case, an influx of hot and corrosive exhaust gas is prevented in the actuator assembly in the direction of the actuator and a correspondingly directed heat conduction. A negative effect of the increased negative pressure on the actuator is prevented thanks to the pressure compensation arrangement. The geometry may for example be designed such that a negative pressure generated at a defined flow through the line section of the exhaust line is sufficiently large to suck the fluid through the actuator assembly in the exhaust line without having to provide additional drive means for the fluid. Such a configuration thus enables a purely passive fluid supply.

Preferably, the geometry of the exhaust line in the form of a so-called Venturi nozzle with a locally narrowed flow cross-section configured and arranged the line branch in the region of the narrowed flow cross-section. The narrowing of the flow cross-section causes a maximum dynamic pressure and the local static pressure in this area Pressure is minimal. At the same time, the static pressure in the connecting section, which opens into the restricted flow cross-section, decreases. This creates a pressure difference, which is used for suction of the supplied fluid. In other words, so the increased negative pressure sucks the fluid from the actuator assembly in the exhaust line.

The active exhaust system may be coupled to an internal combustion engine, in particular a diesel or gasoline engine, for discharging exhaust gases. In addition to vehicles with pure combustion engines, the active exhaust system can also be used in hybrid vehicles. The proposed actuator arrangement allows such effective ventilation or cooling that a corresponding active exhaust system can be used not only for low exhaust gas temperatures of diesel engines, but also for relatively hot exhaust gases of gasoline engines.

According to a further embodiment, the connecting portion of the actuator assembly is formed such that it is tubular in the exhaust line extends and supplies the supplied fluid in a remote from a radial edge region of the exhaust line, radially central region of the exhaust line. Preferably, the connecting portion projecting into the exhaust passage is formed "snorkel-shaped", i. bent at an opening into the exhaust line end in the flow direction for supplying the fluid into the exhaust gas flow, wherein a flow direction of the fluid is substantially rectified to the exhaust gas flow.

• Zuführen von Fluid in den Verbindungsabschnitt der Aktoranordnung zu einer Temperatur- oder Druckkompensation der aktiven Abgasanlage.

Furthermore, a method is proposed for operating an actuator arrangement for an active exhaust system, wherein the actuator arrangement is designed according to the description, with the following step:

• Supplying fluid in the connecting portion of the actuator assembly to a temperature or pressure compensation of the active exhaust system.

• Erfassen mindestens eines Fahrzeugparameters und/oder Erfassen einer Änderung mindestens eines Fahrzeugparameters,
• Ansteuern der Aktoranordnung in Reaktion auf den erfassten Fahrzeugparameter bzw. auf eine Änderung des Fahrzeugparameters.

Furthermore, the step of supplying fluid may comprise the following steps:

• Detecting at least one vehicle parameter and / or detecting a change of at least one vehicle parameter,
• Driving the actuator assembly in response to the detected vehicle parameter or to a change in the vehicle parameter.

In this case, controlling the actuator arrangement may comprise activating the pressure compensation arrangement and / or the actuator and the at least one vehicle parameter may include a temperature value, a pressure value, a vehicle state, a driving state, a load state of a drive unit and / or a coasting operation.

The at least one vehicle parameter can be stored as a predefined value or detected or determined by means suitable in current operation.

For example, the activation of the pressure compensation arrangement comprises switching and / or regulating the pressure compensation arrangement, in particular of a valve included.

In addition, a control device for carrying out a method for controlling an actuator arrangement is provided, wherein the control device is designed to carry out the described method. This can be, for example, a control unit of the actuator (actuator control unit) or a control unit or an engine control unit of an associated vehicle.

By means of the described actuator arrangement or the corresponding active exhaust system, a thermal operating range of the actuator is expanded and allows a more compact design, in which a spatial proximity of the actuator to the hot exhaust system can be made possible. In addition, an insert can also be used for engines with high power levels and associated higher exhaust gas temperatures.

• Fig. 1 einen Verbrennungsmotor mit aktiver Abgasanlage gemäß dem Stand der Technik,
• Fig. 2 eine erste Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung,
• Fig. 3 eine zweite Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung,
• Fig. 4 eine dritte Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung,
• Fig. 5 eine vierte Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung,
• Fig. 6 eine fünfte Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung, und
• Fig. 7 eine sechste Ausführungsform eines Abgasstrangs einer aktiven Abgasanlage mit einer Aktoranordnung gemäß der Beschreibung.

The invention will be described below with reference to the drawings with reference to several embodiments. Show it:

• Fig. 1 an internal combustion engine with active exhaust system according to the prior art,
• Fig. 2 A first embodiment of an exhaust system of an active exhaust system with an actuator arrangement according to the description,
• Fig. 3 A second embodiment of an exhaust system of an active exhaust system with an actuator arrangement according to the description,
• Fig. 4 A third embodiment of an exhaust system of an active exhaust system with an actuator arrangement according to the description,
• Fig. 5 A fourth embodiment of an exhaust system of an active exhaust system with an actuator arrangement according to the description,
• Fig. 6 a fifth embodiment of an exhaust system of an active exhaust system with an actuator assembly according to the description, and
• Fig. 7 a sixth embodiment of an exhaust system of an active exhaust system with an actuator assembly according to the description.

Fig. 1 shows an internal combustion engine 10 of a vehicle with active exhaust system 11 according to the prior art. The active exhaust system 11 is connected to the internal combustion engine 10 for discharging generated exhaust gases and in the illustrated embodiment has an exhaust line 12, which downstream only by way of example includes a pre-silencer 13, a subsequently arranged center silencer 14 and a rear silencer 15. In the case of a multi-flow exhaust system, this can be divided into several exhaust lines (not shown). Exhaust line 12 ends with an end piece 16, through which the exhaust gases pass out into an environment.

Between the rear silencer 15 and the end piece 16, a line branch 17 is arranged, which is designed in the illustrated embodiment Y-shaped and an actuator assembly 18 gas leading to the exhaust line 12 and a line section of the exhaust line 12 connects.

The actuator arrangement 18 comprises an actuator 18a in the form of a loudspeaker, which is arranged in a substantially closed housing and is connected in gas-conducting manner to the exhaust gas line 12 via a connecting element 18b.

The actuator 18a is intended to generate sound waves, which are passed through a arranged in the connecting element 18b standing air column in the exhaust line 12. There, the sound waves superimpose the combustion noises of the internal combustion engine 10 transported via the exhaust gas line 12 with the exhaust gas.

Fig. 2 shows a line branch 27 for a first embodiment of an exhaust line 22 of an active exhaust system 21 with an actuator assembly 28 as described. The arrangement differs from the arrangement in FIG Fig. 1 in particular by the design of the Actuator 28, so that with respect to functional relationships of the other components to the description Fig. 1 unless otherwise stated. The same applies to the following Fig. 3 to 7 ,

The actuator assembly 28 accordingly includes an actuator 28a, which comprises a connecting section 28b or the exhaust line 22 facing the speaker 28c with a membrane 28d. The actuator arrangement 28 has a pressure compensation arrangement 29, which is designed to supply fluid F. In the illustrated case, ambient air is supplied from an environment of the actuator arrangement 28 with a barometric pressure PA into the connection section 28b. For this purpose, the pressure compensation arrangement 29 is associated with the connecting portion 28b in the illustrated embodiment. The pressure compensating assembly 29 includes a recess or opening 29a in a side wall of the connecting portion 28b. Optionally, as shown, the pressure compensation assembly 29 may include an additional tubular inlet disposed in the region of the opening 29a.

The connecting section 28b opens via the branch line 27 into the exhaust line 22, which is traversed by an exhaust gas flow A with an exhaust gas temperature T1 in the direction of the tail pipe 26. The exhaust gas flow A and its temperature T1 are inter alia dependent on a current load state of the vehicle. As it flows through the line branch 27, a negative pressure region U is generated with a negative pressure P1 (static pressure P1) due to a geometry of the line branch 27. This sucks the gas contained in the connecting portion 28b or the fluid F in the exhaust line 22, in which this is supplied together with the exhaust gas flow A through the tailpipe 26 of the environment.

The supply of fluid F by the pressure compensation arrangement 29 causes a certain pressure equalization between the negative pressure P1 and the ambient pressure PA is achieved in the actuator assembly 28, so that a in In this way, a pressure difference can be reduced between a front side of the loudspeaker diaphragm 28d facing the exhaust gas line 22d (Static pressure P3) and a rear side arranged opposite thereto (pressure P4) in consequence of the negative pressure range U exists. Accordingly, the pressure P3, depending on the circumference of a deliverable volume flow of the fluid F, lies between a barometric air pressure PA and the negative pressure P1, which in turn depends on the exhaust gas mass flow.

Thus, a deflection of the loudspeaker diaphragm 28d of the actuator 28a in a non-actuated state of the actuator 28a due to the applied pressure difference can be reduced and thus an efficiency of the actuator 28a can be increased.

The actuator 28a may optionally have a pressure compensation opening 28e, which ensures a pressure equalization between the ambient pressure PA and the pressure P4 prevailing on the rear side of the loudspeaker diaphragm 28d.

Fig. 3 shows a line branch 37 for a second embodiment of an exhaust line 32 of an active exhaust system 31 with an actuator assembly 38 as described. This essentially corresponds to the actuator arrangement 28 Fig. 2 so that reference may be made to the given description.

However, differences arise in particular in the design of the pressure compensation arrangement 39. This comprises an opening 39a, which is provided in the actuator arrangement 38 and designed to supply the fluid into the connection section 38b. The pressure compensation arrangement 39 further comprises a valve 39b, which is arranged in the region of the opening 39a such that by means of the valve 39b, the supply of the fluid depending on Design of the valve can be switched or even regulated. This means that the valve is either switchable between an open and a closed position, or is adjustable between several intermediate positions.

Fig. 4 shows a manifold 47 for a third embodiment of an exhaust line 42 of an active exhaust system 41 with an actuator assembly 48 as described. This essentially corresponds to the actuator arrangement 38 Fig. 3 so that reference may be made to the given description.

However, differences arise in particular in the design of the pressure compensation arrangement 49. This also includes an opening 49a which is provided in the actuator arrangement 48 and designed to supply fluid into the connection section 48b. The pressure compensator assembly 49 also includes a valve 49b but spaced apart from the opening 49a by a conduit member 49c. The conduit member 49c is hose-shaped in the illustrated embodiment, and allows the spatial spacing of the valve 49b to the opening 49a, for example, to reduce contamination. The fluid is supplied by entering the fluid into the valve 49b, passing the fluid through the conduit member 49c, and entering the connection portion 48b via the opening 49b.

Fig. 5 shows a line branch 57 for a fourth embodiment of an exhaust line 52 of an active exhaust system 51 with an actuator assembly 58 as described. This essentially corresponds to the actuator arrangement 48 Fig. 4 so that reference may be made to the given description.

However, differences arise in particular in the design of the pressure compensation arrangement 59. This comprises an opening 59a, which in the Actuator 58 is provided and is designed to supply the fluid in the connecting portion 58 b. The pressure compensation assembly 59 also includes a conduit member 59c which is tubular and connected at a first end to the opening 59a. An opposite second free end may optionally include a valve 59b. Also optionally, the pressure compensating assembly 59 may include a filter 59d which is also disposed in or on the conduit member 59c as appropriate. For example, filter 59d may be integrated with or spatially separated from valve 59b.

Fig. 6 shows a manifold 67 for a fifth embodiment of an exhaust line 62 of an active exhaust system 61 with an actuator assembly 68 as described. Accordingly, the exhaust line 62 is formed in the region of the line branch 67 in its geometry for amplifying the negative pressure region U. This is achieved by a local cross-sectional constriction of the exhaust line 62 in the form of a Venturi nozzle and leads under the conditions prevailing in an exhaust system conditions to an increase in the flow rate with simultaneous local pressure reduction. A negative pressure range U with the static pressure P1 (negative pressure) is thus increased, and in absolute terms the static pressure P1 is further lowered.

As a further difference from the embodiments described above, the pressure compensation assembly 69 is not arranged in a wall of the connecting portion 68b, but in a housing of the actuator 68a, but on a side facing the exhaust line 62, so that the supplied fluid also via the housing of the actuator 68a is supplied to the connection section 68b. This feature is independent of the configuration of the geometry of the manifold and can therefore also be combined with the other described embodiments.

Also optional and can be combined with other embodiments is a thermal shield 68f of the actuator 68a or its housing.

Fig. 7 shows a manifold 77 for a sixth embodiment of an exhaust line 72 of an active exhaust system 71 with an actuator assembly 78 as described.

This essentially corresponds to the one in Fig. 6 described arrangement, so that reference is made to the description given there.

However, a significant difference arises from the configuration of the pressure compensation arrangement 79 of the actuator arrangement 78. The pressure compensation arrangement 79 comprises a cooling jacket which at least partially overlies a housing of the actuator 78a. For this purpose, a line element 79c of the pressure compensation arrangement 79 is designed as a cooling channel and extends over an outer surface of the actuator 78a.

In any case, an open end of the conduit member 79c is provided, in which the fluid F can flow. Subsequently, this flows through the cooling channel of the line element 79c designed as a cooling jacket and enters the housing of the actuator 78a at an other end of the line element 79c through an opening 79a for supplying the fluid into the connecting element 78b.

Alternatively, the opening 79a may also be arranged in a wall of the connecting element 78b and / or the cooling jacket may be designed to cool the actuator arrangement 78 or at least one section.

In other words, therefore, the fluid, that is, for example, the intake ambient air, can be additionally used as a thermal insulator using a capsule around the actuator. The fluid is guided in a gap between the capsule and the actuator housing. To this In this way, the uncoupled back volume on the back of the loudspeaker can be cooled or thermally isolated from the environment. This is all the more important, since the most temperature-critical components, in particular magnets, are located in the back volume. It should also be noted that the capsule can completely or only partially enclose the housing, in principle also an additional tube is possible, which leads the fluid after entering the actuator housing even closer to the membrane surface.

Claims (15)

Actuator arrangement for active exhaust systems for generating a sound signal with at least one actuator (28a, 68a, 78a) "wherein the actuator assembly (28,38,48,58,68,78) at least with a connecting portion (28b, 38b, 48b, 58b, 68b , 78b) gas-conducting with at least one exhaust line (22,32,42,52,62,72) of the exhaust system (21,31,41,51,61,71) is connectable,
characterized in that
the actuator assembly (28, 38, 48, 58, 68, 78) has a pressure compensating assembly (29, 39, 49, 59, 69, 79) for supplying fluid (F) into the connecting portion (28b, 38b, 48b, 58b, 68b , 78b). Actuator arrangement according to claim 1, characterized in that the pressure compensation arrangement (29,39,49,59,69,79) at least one recess (29a, 39a, 49a, 59a, 79a) and / or at least one conduit member (49c, 59c, 79c ) for supplying the fluid (F) into the gas-conducting connection portion (28b, 38b, 48b, 58b, 68b, 78b) of the actuator assembly (28, 38, 48, 58, 68, 78). Actuator arrangement according to one of claims 1 or 2, characterized in that the supplied fluid (F) air, in particular ambient air, is. Actuator arrangement according to one of claims 1 to 3, characterized in that the pressure compensation arrangement (29,39,49,59,69,79) a valve (39b, 49b, 59b), a controllable and / or controllable valve and / or a Filter (59d), wherein the controllable and / or controllable valve is electrically, hydraulically and / or pneumatically controllable Actuator arrangement according to one of claims 1 to 4, characterized in that the pressure compensation arrangement (29,39,49,59,69,79) the actuator (28a, 68a, 78a) and / or the connecting portion (28b, 38b, 48b, 58b , 68b, 78b). Actuator arrangement according to one of claims 2 to 5, characterized in that the at least one line element (79c) comprises at least in sections a cooling channel for cooling the actuator assembly (78). Actuator arrangement according to one of claims 1 to 6, characterized in that the actuator assembly (68) is formed at least partially insulated from an environment thermally insulated. Active exhaust system with an exhaust system and a gas-conducting with the exhaust line actuator assembly (28,38,48,58,68,78), characterized in that the actuator assembly (28,38,48,58,68,78) according to any one of claims 1 to 7 is formed. Active exhaust system according to claim 8, characterized in that a compound of the connecting portion (28b, 38b, 48b, 58b, 68b, 78b) of the actuator assembly (28,38,48,58,68,78) with the exhaust line as a Y-shaped Line branch (27,37,47,67,77) is configured. Active exhaust system according to claim 8 or 9, characterized in that a geometry of the exhaust line (22,32,42,52,62,72) at least in the region of a line branch (27,37,47,67,77) for forming a flow-induced negative pressure for sucking fluid (F) from the actuator arrangement (28, 38, 48, 58, 68, 78) into the exhaust line (22, 32, 42, 52, 62, 72), the line branch (27, 37, 47, 67, 77) a connection between the connecting section (28b, 38b, 48b, 58b, 68b, 78b) of the actuator assembly (28,38,48,58,68,78) with the exhaust line (22,32,42,52,62,72) defined. Active exhaust system according to claim 10, characterized in that the geometry of the exhaust line (22,32,42,52,62,72) is designed in the form of a Venturi nozzle with a locally narrowed flow cross section and the line branching (27,37,47, 67,77) is arranged in the region of the narrowed cross section. A method of operating an actuator assembly for an active exhaust system, wherein the actuator assembly according to any one of claims 1 to 7 is formed, comprising the following step: - Supplying fluid into a connecting portion of the actuator assembly to a temperature or pressure compensation of the active exhaust system. The method of claim 12, wherein the step of supplying comprises the steps of: Detecting at least one vehicle parameter and / or detecting a change of the vehicle parameter, - Actuating the actuator assembly in response to the detected vehicle parameters or to a change in the vehicle parameter. 13. The method of claim 13, wherein driving the actuator arrangement comprises activating the pressure compensation arrangement and / or the actuator and the at least one vehicle parameter includes a current temperature value, a current pressure value, a current vehicle state, a driving state, a load state of a drive unit and / or a coasting operation. Control unit for carrying out a method for controlling an actuator arrangement, characterized in that the control unit is designed to carry out the method according to one of claims 12 to 14.

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