DE102010005138A1 - Motor vehicle has electronic sound generating system with electrical vibration generator and electrical vibration generator that is fixed at baffle board, where baffle board is acoustic decoupled by body or frame of motor vehicle - Google Patents

Abstract

The motor vehicle has an electronic sound generating system with an electrical vibration generator (20). The electrical vibration generator is fixed at a baffle board (8,12). The baffle board is acoustic decoupled by a body or a frame of the motor vehicle. The sound is radiated in the surrounding of the motor vehicle by the baffle board. An independent claim is also included for an exhaust silencer for a motor vehicle, which has an outer wall.

Description

The invention relates to a motor vehicle and an exhaust system for a motor vehicle.

In the design and development of motor vehicles, there has recently been a growing need to be able to specifically influence or adapt the sound image which the motor vehicle generates in its surroundings.

In view of this need, it is an object of the invention to be able to influence the sound image, which achieves the motor vehicle in its environment, in a simple manner in motor vehicles to selectively produce a desired sound impression can. This object is achieved by a motor vehicle having the features specified in claim 1 and by an exhaust system with the features specified in claim 15. Preferred embodiments will become apparent from the appended subclaims, the following description and the attached figures.

According to the invention, the acoustic adaptation of the exterior noise of the motor vehicle is provided by an electronic sound generation system. With this targeted a desired sound image can be created, which may also be changed depending on the driving conditions by electronic control. In this case, in particular the natural, for example, generated by the internal combustion engine of a motor vehicle sound can be changed or selectively supplemented by an additional sound spectrum to produce a targeted overall external noise of the vehicle can.

The electronic sound generation system has an electrical vibration exciter, which converts electrical signals generated by control electronics into mechanical vibrations for generating sound. The electrical vibrator may, for example, piezoelectric, electrostatic, magnetic or work in any other suitable manner. Preferably, it is an electromagnetic vibration exciter as he, for example DE 10 2008 049 560 is known. The vibration exciter is attached to a baffle which is vibrated by the electrical vibration exciter due to its periodic mechanical deflection, so that the baffle radiates the desired sound. According to the invention, it is provided that this baffle is acoustically decoupled from the body and / or a frame of the motor vehicle, so that sound is radiated from the baffle essentially only to the surroundings of the motor vehicle, but the vibrations of the baffle do not affect the body or the baffle Frame of the motor vehicle are transmitted. Thus, it is achieved, for example, that the sound image can be perceived essentially outside the motor vehicle, but is not transmitted to the interior via the body and leads there to undesired noise. According to the invention, the exterior noise of the vehicle should preferably be modified or optimized.

To achieve this, more preferably, the baffle with the vibration exciter outside a passenger compartment or outside the body arranged. For example, the baffle can be arranged in the underbody area below the body. This ensures that the radiated sound substantially does not penetrate into the interior of the vehicle.

More preferably, the baffle is formed as a membrane or it is a membrane disposed in the baffle to which the vibration exciter is attached. This is particularly preferred when the baffle to which the vibration exciter is to be attached has an overall rigidity which does not allow the baffle to be translated into the desired vibrations to radiate the desired sound. The membrane is preferably made of a sufficiently thin sheet metal or a metal foil with the required spring action. Preferably, a material having sufficient heat resistance is used, which makes it possible to use in areas of the motor vehicle which are exposed to a heat effect. This can be, for example, a use in the exhaust system. The vibration exciter is firmly connected to the membrane in a suitable manner, for example screwed or glued.

It is possible that the entire baffle is formed as a membrane. Alternatively, it is possible that in the baffle a specific area is formed as a membrane or in a recess of the baffle a membrane is used. Thus, the membrane may be formed integrally with a wall circumferentially adjacent to the membrane or fixedly connected to a wall circumferentially adjacent to the membrane. In the case that the surrounding wall is also made of metal, the membrane may be welded to this wall, for example. However, it is also conceivable kraft-, form- or in other ways substance-liquid compounds. It is also possible to form the membrane integrally with a surrounding wall of thicker material thickness, for example by making the membrane as a thinned portion in the wall.

The membrane preferably has elastic or resilient regions in which the membrane can spring very strongly. This can be done by suitable shaping can be achieved, for example, by a wave-shaped or arc-shaped cross section in the edge region of the membrane.

Particularly preferably, the membrane has a stiff central region, to which the vibration exciter is attached and which is surrounded by an elastic region. Thus, the rigid or substantially rigid central region can preferably oscillate in a non-deforming manner along a linear axis. In this case, this central region can be designed flat and extend normal to the axis of movement of the membrane. Alternatively, the central region can also be conical, curved or conical, preferably concentric with the axis of movement. The mobility of this stiff central region is achieved by the surrounding elastic region, which is formed for example by suitable shaping. For example, the elastic region may be wave-shaped or arc-shaped in cross-section, so that the shape, together with the elasticity of the material, achieves the desired spring effect and spring rigidity. The rigid central region can be created by thicker membrane formation in this region. It is also possible that in this area a reinforcing element, for example in the form of a rigid plate, in particular a metal plate is attached to which then preferably also the vibration exciter is attached.

As described above, the vibration exciter may preferably be a magnetic vibration exciter. It is further preferred that a coil arrangement of the magnetic vibration exciter is attached to the baffle, while a magnet arrangement of the vibration exciter is movable relative to the coil arrangement. By energizing the coil is built around this a magnetic field, which interacts with the magnetic field of the magnet assembly and thereby generates a relative movement between the coil assembly and magnet assembly. In this way, a mechanical vibration is generated when the coil is excited with a corresponding electrical vibration. According to the described embodiment, the coil arrangement is preferably fixedly arranged on the baffle or on the membrane, while the magnet arrangement is movable relative to the coil arrangement. Due to the inertia of the magnet arrangement vibrations are transmitted to the baffle or its membrane in this embodiment.

The coil arrangement and the magnet arrangement are preferably connected to one another via at least one spring element. In this case, the connection is preferably designed such that the magnet arrangement can oscillate relative to the coil arrangement along a longitudinal axis. Magnet arrangement and coil arrangement can be guided mechanically along this longitudinal axis in their movement, as for example from DE 10 2008 049 560 is known. Thus, the spring elements between the coil assembly and magnet assembly preferably do not absorb undesirable transverse forces.

According to a preferred embodiment, the baffle may have a finite extent. That is, the baffle forms a limited, in particular plane, but possibly also suitably curved or profiled surface, in which optionally, as described above, a membrane may be arranged or formed. Alternatively, the entire baffle can take over the function of the membrane. In this embodiment, the vibration exciter is preferably attached to a surface of the baffle. The baffle expediently know a size and / or shape, which prevents an acoustic short circuit between the front and back.

In a further preferred embodiment, the baffle can have an infinite extent by being formed as a wall of a hollow body. In this case, the hollow body is preferably acoustically decoupled from a body and / or a frame of the Karftfahrzeuges. The hollow body forms, for example, a closed container or, if necessary, one or more sides open container whose wall forms the baffle. It may optionally be formed in the wall, a membrane according to the foregoing description. At least one vibration exciter is then preferably arranged on the baffle and / or the membrane. By the acoustic decoupling of the body and / or a frame, for example via suitable damping elements, it is prevented that while the vibrations of the hollow body are transmitted to the body and thus in the interior. In this embodiment, the hollow body includes an air or gas volume of defined spring stiffness for the sound generator formed from the baffle or membrane and the vibration generator.

Preferably, the vibration exciter is attached to the outside of the hollow body. This allows for a very simple installation, on the other hand, the interior of the hollow body can be used for other purposes. The vibration exciter is further preferably encapsulated or sealed so that it can be expediently also in the outer region of a motor vehicle in which it is exposed to weathering, can be used. The out DE 10 2008 049 560 known vibration exciter z. B. in principle suitable for this purpose.

In particular, the hollow body may be part of an exhaust system, in particular an exhaust silencer. Such exhaust systems and exhaust mufflers are present in conventional motor vehicles anyway, so that can be dispensed with additional components for mounting the vibration exciter here. In addition, they are usually optimally acoustically decoupled from the body or a frame of the motor vehicle and form a volume which can be used for the sound generator. Thus, the vibration exciter may preferably be arranged on the outside of an exhaust silencer, for which purpose a membrane can be arranged or formed in the wall of the exhaust silencer. The wall thickness of the sheet of conventional exhaust muffler is usually too thick to be able to vibrate this so that it emits a desired sound. In this arrangement in the exhaust muffler is essential that the sound or generated by the vibration generator on the baffle or membrane in the wall of the muffler noise image is given to the outside in the environment. This takes place on the one hand directly on the outside of the wall of the exhaust muffler to the other possibly also partially on the exiting from the exhaust gas. Preferably, the main purpose of the sound generator formed in this way in the exhaust system is not to dampen the sound transmitted by the exhaust gas by corresponding countervibrations, but to supplement the sound transmitted by the exhaust gas by an additional sound pattern or an additional background noise to a total desired Sound, for example, engine sound to radiate outward into the environment of the motor vehicle. Thus, the engine and exhaust sound of a motor vehicle can be changed or optimized much easier than would be possible by appropriate design of the flow guide and damping elements in the interior of the exhaust system.

In particular, the present invention can also be used in an at least partially or further preferably completely electrically driven motor vehicle. In the case of partially or completely electrically driven vehicles, the problem arises that they produce substantially no externally perceptible operating noise during electrical operation. On the one hand, the user of the motor vehicle possibly lacks something here, namely the typical sound of a motor vehicle. On the other hand, this results in a security risk, since pedestrians and in particular visually impaired persons can perceive such vehicles in the traffic much worse. For this reason, it may be desirable, especially with partially or completely electric vehicles, to provide them with an artificially created sound image which is emitted to the environment. At the same time, however, one might want to achieve a different, in particular lower, background noise in the interior. For this reason, the above-described sound generating system is advantageous, since this can be arranged with the decoupled from the body or the frame of the motor vehicle baffle on the outside of the motor vehicle, so that the generated vibrations or noises not on the structure of the body or of the frame are transmitted to the interior of the vehicle.

As described above, the sound generation system preferably has control electronics which output electrical signals to the at least one vibration exciter. These electrical signals can be calculated in the control device according to algorithms stored there or based, for example, on stored signal patterns. In this case, the control electronics are further preferably designed such that they generate the electrical signals on the basis of at least one parameter detected in the motor vehicle. This parameter can be, for example, the engine speed, the driving speed and / or a detected noise level, as a function of which corresponding electrical signals for excitation of the vibration exciter are generated. These can then be generated and output based on predetermined algorithms or values previously stored in the control electronics. Thus, for example, a speed or speed-dependent external noise can be generated on the motor vehicle.

The invention also relates to an exhaust system for a motor vehicle, in which an electrical vibration generator of a sound generator system is arranged on the outside of an outer wall of the exhaust system, in particular on the outside of an exhaust muffler. This Schallerzeugungssytem can be designed in the manner described above with reference to the entire motor vehicle. The arrangement of the vibration generator on the outside of the exhaust system or an exhaust silencer has the advantage that the vibration generator does not have to be exposed to the unfavorable environmental conditions inside the exhaust or the exhaust system, in particular not there prevailing high temperatures. This allows for a simpler construction of the vibration exciter and ensures on the other hand, a higher reliability and durability of the vibration exciter.

Preferably, as described above, arranged or formed in the outer wall of the exhaust system, in particular a muffler, a membrane to which the vibration generator is mounted in the manner described above. For the rest, reference is made to the above description with regard to the design of the sound generation system.

The invention will now be described by way of example with reference to the accompanying drawings. In these shows:

1 Partially partially schematically illustrates an exhaust muffler with an integrated sound generation system,

2 - the exhaust silencer according to 1 in perspective side view,

3 - schematically the operation of the vibrator and

4 Schematically a motor vehicle according to the invention.

Based on 1 and 2 a first possibility of the arrangement of a sound generating system in a motor vehicle is explained. In this embodiment, a sound generation system is in the exhaust muffler 2 a motor vehicle integrated. The exhaust silencer 2 is shown here schematically without its internal structure. The exhaust silencer 2 is in a conventional manner in an exhaust pipe or an exhaust pipe 4 located. In the example shown, it is the final muffler from which the tailpipe starts 6 extends. The wall 8th , which the hollow body of the exhaust muffler 2 defines, forms an infinite baffle, which is used for the sound generation system. This is in the wall 8th a recess 10 introduced, for example cut into which a membrane 12 is welded. That is the membrane 12 is at its outer periphery with the edge of the recess 10 welded. However, it is also another connection, such as a positive or non-positive connection conceivable. In the example shown here is the membrane 12 circular, but it should be understood that the membrane may have other shapes as well. The diaphragm has a resilient region near its outer periphery, formed by a curvature in its cross section 14 on. In its central area is the membrane 12 through an additional plate 16 For example, reinforced aluminum on its outside. The membrane itself is formed as a metal foil, which has a suitable elasticity and is also heat-resistant, which is required in the application in the exhaust system.

At the plate 16 is over the bolt 18 an electrical or an electromagnetic vibration exciter arranged. This vibration exciter corresponds for example to the in DE 10 2008 169 560 disclosed vibrational exciters. The vibration generator 20 has a magnet arrangement 22 and a coil assembly 24 on, which in the direction of the longitudinal axis X of the bolt 18 are movable relative to each other. In this case, the coil arrangement 24 firmly on the bolt 18 attached and thus on this to the membrane 12 established. The magnet arrangement 22 is with the coil assembly 24 about springs 26 and 28 connected and axially movable on the bolt 18 guided. So can the magnet arrangement 22 in the direction of the longitudinal axis X relative to the coil assembly 24 move or swing relative to this. Through the guide on the bolt 18 is it possible to use the vibration exciter 20 Also to arrange differently than in the vertical direction, as occurring lateral forces of the bolt 18 be absorbed and not affect the vibration behavior. By energizing a coil of the coil assembly 24 with an electrical vibration signal is in the vibration exciter between the magnet assembly 22 and the coil assembly 24 generates a mechanical vibration, ie coil arrangement 24 and magnet assembly 22 swing relative to each other, with this vibration over the bolt 18 on the membrane 12 is transmitted. The membrane 12 is thus also vibrated and thus generates sound waves, which outwardly, preferably to the outside of the exhaust muffler 2 be radiated out. The membrane 12 also radiates sound waves inward into the exhaust muffler 2 from. Through the wall 8th of the case while an acoustic short circuit is prevented. Part of the inside of the muffler 2 generated sound is through the tailpipe 6 also escape to the outside.

The vibration generator 20 forms with the membrane 12 a spring-mass system, as shown schematically in 3 is shown. The whole system is in the present example at the baffle 8th which is considered a fixed base. The system has two masses M1 and M2, the mass M1 being the mass of the coil arrangement 24 and the membrane 12 with the plate 16 is. The mass M2 is the mass of the magnet arrangement 22 , The spring constant F1 corresponds to the spring constant of the membrane 12 and in particular their resilient region 14 plus the spring constant of the gas volume enclosed in the hollow space behind the membrane. The spring constant F2 corresponds to the spring constant of the springs 26 and 28 which between the magnet arrangement 22 and the coil assembly 24 Act. The vibration generator 220 forms with the membrane 12 thus a double spring-mass oscillator, which can also produce low-frequency sound with appropriate coordination of the masses and spring constants.

The arrangement of the vibration exciter 20 outside the exhaust pipe 4 and the exhaust muffler 2 has the advantage that the vibration exciter 20 not the condensate and the high temperatures inside the exhaust pipe 4 and the exhaust muffler 2 is exposed. This makes it possible to elaborate encapsulation of the vibration exciter 20 to dispense, and allows the vibration exciter 20 much easier to design because it is not exposed to the high loads inside the exhaust system. Rather, the ambient air of the exhaust muffler allows 2 a good cooling of the vibration exciter 20 , In addition, sound is preferably emitted directly to the outside, whereby the sound image of the motor vehicle in the outdoor area can be well influenced.

4 shows schematically the arrangement of the exhaust muffler 2 on a motor vehicle 30 , The exhaust silencer 2 is like the exhaust pipe 4 via damping elements 32 with the body 34 connected and so optimal of the body 34 acoustically decoupled. This acoustic decoupling is in any case present in conventional exhaust systems or exhaust systems. In this respect, the installation of the sound generation system consisting of vibration exciter 20 and membrane 12 in the exhaust system advantageous because there anyway a decoupled baffle in the form of the wall 8th the exhaust silencer 2 is available. It is thus not necessary, an additional component decoupled from the body 34 to be used as a baffle. In addition, a sound radiation is generated exactly where in conventional motor vehicles with internal combustion engine already exists a sound radiation. In this respect also results in the additional artificial sound generation via the vibration exciter 20 a natural-looking sound radiation from the motor vehicle 30 which emanates from the same places, from which naturally emanates the sound generated by the engine of the motor vehicle. In that respect can with the vibration exciter 20 and the membrane 12 the sound of the exhaust are additionally supported and in particular the sound produced by the exhaust are supplemented by additional sound components to produce a desired sound image.

This system can also be used in partially or fully electrically powered vehicles. In partially electrically powered vehicles, which additionally have an internal combustion engine, still offers the arrangement of the vibrator 20 on the exhaust silencer 2 an exhaust system. In fully electrically powered vehicles, such an exhaust system is not present. In such vehicles, for example, a hollow body corresponding to the exhaust muffler 2 via damping elements 32 decoupled on the outside of the body 34 be attached to which then in the manner described here, a vibration exciter 20 is attached. Such a system would thus essentially the system described here on the exhaust silencer 2 correspond, only the exhaust pipe 4 and the tailpipe 6 and usually inside the exhaust muffler 2 existing sheets and flow guides could be omitted. In this respect, electric vehicles with this system will also be able to radiate defined sounds to the outside, so that they are not completely silent.

To generate the drive signals for the vibration exciter 20 is in the motor vehicle 30 an electronic control system 36 provided, which can generate corresponding control signals, for example, speed-dependent or speed-dependent. The control electronics 36 is for example via a line 38 with the vibration exciter 20 connected. However, it is also conceivable, the control electronics 36 directly on the vibration exciter 20 to arrange and supply only possibly required input parameters via data lines of the control electronics. Also, a vibration exciter with integrated sensor can be used as the vibration exciter, we him from DE 10 2009 021 466 for example, is known.

The use of a vibration exciter with an integrated sensor also provides the opportunity to capture the input variables for the signal generation for the vibration generator directly on the vibration exciter itself. When arranged in the exhaust system of an internal combustion engine, for example, it is possible by the sensor, for example a sensor coil in the vibration exciter, pressure fluctuations in the exhaust gas, d. h., To detect gas shocks directly on the vibration exciter. From these gas shocks information about speed, coasting, load torque and the like of the drive can be derived from frequency, amplitude and spectrum and then based on these variables by a control device or control electronics corresponding electrical input signals are generated for the vibration exciter, for example by means of the vibration exciter in Exhaust system to produce a speed-dependent engine sound.

In the arrangement described above, such gas shocks would, for example, cause the diaphragm or baffle to vibrate mechanically causing the coil assembly 24 relative to the magnet assembly 22 deflected, which would be deflected by a corresponding sensor, for example, an additional sensor coil, as they are made DE 10 2009 021 466 is known, could be detected.

Instead of the baffle possibly with an additional membrane decoupled from the body 34 as an additional component to arrange this, it is also conceivable, a membrane 12 as baffle directly into a body panel to integrate. The decoupling of this membrane would then preferably take place via the resilient or elastic region of the membrane, so that preferably only a central region of the membrane is set in vibration and the body region surrounding the membrane is kept free of vibrations, so that even in this arrangement the interior of the motor vehicle 30 is kept free of the generated sound as far as possible.

In the example shown, the motor vehicle is shown as a car. It should be understood that the motor vehicle could also be a truck or, for example, a motorcycle, in which case the body would essentially correspond to the frame of the motorcycle. Also, a corresponding arrangement would be possible in air and water vehicles, which are thus also considered as motor vehicles in the context of this invention.

LIST OF REFERENCE NUMBERS

2

exhaust silencer

4

exhaust pipe

6

tailpipe

8th

wall

10

recess

12

membrane

14

resilient area

16

plate

18

bolt

20

vibration exciter

22

magnet assembly

24

Spulenanornung

26, 28

feathers

30

motor vehicle

32

damping element

34

body

36

control electronics

38

management

X

longitudinal axis

M1, M2

masses

F1, F2

Springs or spring constants

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008049560 [0005, 0012, 0015]
• DE 102008169560 [0027]
• DE 102009021466 [0032, 0034]

Claims (16)

Motor vehicle with an electronic sound generation system, which has at least one electric vibration generator ( 20 ), which in such a manner on a baffle ( 8th . 12 ) attached by a body ( 34 ) and / or a frame of the motor vehicle ( 30 ) is acoustically decoupled that from the baffle ( 8th . 12 ) Sound in the environment of the motor vehicle ( 30 ) is radiated. Motor vehicle according to Claim 1, in which the baffle ( 8th . 12 ) with the vibration exciter ( 20 ) outside a passenger compartment or outside the body ( 34 ) is arranged. Motor vehicle according to one of the preceding claims, in which the baffle ( 8th ) as a membrane ( 12 ) or a membrane ( 12 ) in the baffle ( 8th ) is arranged at which the vibration exciter ( 20 ) is attached. Motor vehicle according to Claim 3, in which the diaphragm ( 12 ) in one piece with a peripheral to the membrane ( 12 ) adjacent wall ( 8th ) or fixed with a peripheral to the membrane ( 12 ) adjacent wall ( 8th ) connected is. Motor vehicle according to Claim 3 or 4, in which the membrane ( 12 ) a stiff middle region ( 16 ) on which the vibration exciter ( 20 ) and which of an elastic region ( 14 ) is surrounded. Motor vehicle according to one of the preceding claims, wherein the vibration exciter ( 20 ) is a magnetic vibrator having a coil arrangement ( 24 ), which at the baffle ( 12 ), and a magnet assembly ( 26 ), which relative to the coil arrangement ( 24 ) is movable. Motor vehicle according to Claim 6, in which the coil arrangement ( 24 ) and the magnet arrangement ( 22 ) via at least one spring element ( 26 . 28 ) are interconnected. Motor vehicle according to one of the preceding claims, in which the baffle ( 8th . 12 ) has a finite extent. Motor vehicle according to one of Claims 1 to 7, in which the baffle ( 8th . 12 ) from a wall ( 8th ) of a hollow body ( 2 ), which acoustically from a body ( 34 ) and / or a frame of a motor vehicle ( 30 ) is decoupled. Motor vehicle according to Claim 9, in which the electric vibrator ( 20 ) on the outside of the hollow body ( 2 ) is attached. Motor vehicle ( 30 ) according to one of the preceding claims, in which the hollow body ( 2 ) a part of an exhaust system, in particular an exhaust muffler ( 2 ). Motor vehicle according to one of the preceding claims, which is at least partially electrically driven. Motor vehicle according to one of the preceding claims, in which the sound generation system comprises control electronics ( 36 ), which electrical signals to the at least one vibration generator ( 20 ). Motor vehicle according to Claim 13, in which the control electronics ( 36 ) is configured such that the electrical signals based on at least one in the motor vehicle ( 30 ) generated parameter generated. Exhaust system for a motor vehicle ( 30 ), in which an electrical vibration exciter ( 20 ) of a sound generation system on the outside of an outer wall ( 8th ) of the exhaust system ( 2 ) is attached. Exhaust system according to claim 15, in which in the outer wall ( 8th ) a membrane ( 12 ) is arranged at which the vibration exciter ( 20 ) is attached.

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