WO2020049108A1

WO2020049108A1 - Switchable sound actuator

Info

Publication number: WO2020049108A1
Application number: PCT/EP2019/073714
Authority: WO
Inventors: Gerhard Dochow; Stefan Bieger
Original assignee: Continental Automotive Gmbh
Priority date: 2018-09-05
Filing date: 2019-09-05
Publication date: 2020-03-12
Also published as: DE102018215067A1; DE102018215067B4

Abstract

The invention relates to a switchable sound actuator (1). Said switchable sound actuator comprises a first coupling element (20), a second coupling element (30), a drive (10) and a control unit (40). The first coupling element (20) is fastened to the drive (10), and the first coupling element (20) is designed to be connected to an inner diaphragm surface (21). The control unit (40) is designed to apply an electrical signal (50), which corresponds to an acoustic signal, to the drive (10), which electrical signal triggers the drive (10) to cause the inner diaphragm surface (21), which is connected to a first end (10a) of the drive (10), to vibrate such that the acoustic signal is emitted by the inner diaphragm surface (21). The second coupling element (30) is designed to be connected to an outer diaphragm surface (31), and a second end (10b) of the drive (10) is connected to the second coupling element (30). The second coupling element (30) has a material having variable stiffness. The control unit (40) is designed to stiffen the second coupling element (30) in a specific manner such that the drive (10) causes the outer diaphragm surface (31) to vibrate if required, such that the acoustic signal is emitted by the outer diaphragm surface (31).

Description

description

- Switchable sound actuator -

The invention relates to a switchable sound actuator and a vehicle with such a switchable sound actuator.

The development of new vehicles, and in particular electric vehicles, leads to quieter vehicles, since the internal combustion engines are better soundproofed or are eliminated altogether. These vehicles are therefore difficult for other road users, such as a pedestrian, to hear. As a result, a pedestrian may not perceive a vehicle or may notice it too late. To avoid this, vehicles can have devices that generate an artificial driving noise so that they are more noticeable to other road users. However, these devices must be installed additionally, which increases the weight of the vehicle.

It is an object of the invention to generate sound in a targeted manner.

This object is achieved by the subject of the independent claims. Embodiments and developments can be found in the dependent claims, the description and the figures.

A first aspect of the invention relates to a switchable sound actuator. This switchable sound actuator has a first coupling element, a second coupling element, a drive and a control unit. The first coupling element is fastened to the drive, for example an electromagnet, and is set up to be connected to an inner membrane surface. The control unit is set up to drive with an electrical signal, which with an acoustic signal Corresponds to act, which causes the drive to vibrate the inner membrane surface, which is connected to a first end of the drive, so that the acoustic signal is emitted from the inner membrane surface. The second coupling element is set up to be connected to an outer membrane surface, a second end of the drive being connected to the second coupling element. The second coupling element has a material with a variable stiffness or viscosity, for example an electrorheological or a magnetorheological material. The control unit is also set up to specifically stiffen the second coupling element, so that the drive causes the outer membrane surface to vibrate as required, so that the acoustic signal is emitted from the outer membrane surface.

With the switchable sound actuator, an acoustic signal can be emitted both internally and optionally externally. A drive can convert an electrical signal generated by a control unit, which corresponds to an acoustic signal or which is modulated by an acoustic signal, into vibrations and transmit this to an inner membrane surface and optionally also to an outer membrane surface, so that this membrane surface is the acoustic signal radiates inwards and optionally outwards. The drive can be connected to the inner membrane surface by means of a first coupling element and to the outer membrane surface by means of a second coupling element. The first coupling element can serve to support the drive and the drive can have a direct connection to the inner membrane surface, in particular the drive can be welded, glued or screwed to the inner membrane surface. The second

Coupling element can have several states, in a first state it can the movements of the drive against the dampen the outer membrane surface. In a second state, the rigidity or the viscosity of the second coupling element can be increased, so that the movements (vibrations) of the drive are also transmitted to the outer membrane surface, so that the outer membrane surface also emits the acoustic signal. In other words, the inner and optionally the outer membrane surface can be excited to vibrate by the drive, as a result of which they emit the acoustic signal, for example a warning tone or an engine noise. This means that the acoustic signal can also be emitted to the outside. This means that an additional sound generator, such as a loudspeaker, does not have to be installed. Weight, installation space and costs can thus be saved.

It should be noted that the switchable sound actuator can be arranged between an inner vehicle panel and an outer vehicle panel, so that these panels act as membrane surfaces. It should be noted that the membrane surfaces can also be plastic or glass parts of the vehicle. Furthermore, the switchable sound actuator can also be used for hands-free and intercom systems, so that an outdoor area can be supplied with an acoustic signal. In other words, the switchable sound actuator can selectively switch the outer membrane surface on or off.

According to one embodiment of the invention, the second coupling element has a magnetorheological or an electrorheological material, in which the rigidity or the viscosity can be influenced by a magnetic or an electrical field.

According to a further embodiment of the invention, the magnetorheological or the electrorheological material is a liquid. For example, the electrorheological Have liquid aluminum salts of stearic acid or polyurethane particles dispersed in a silicone oil as a carrier. The magnetorheological liquids can have magnetic particles in a carrier liquid, for example mineral oil. Both fluids have in common that they change their stiffness or viscosity depending on an electric or magnetic field. Furthermore, it should be noted that the control unit can control the rigidity in a targeted manner, so that a desired rigidity can be generated and thus a desired intensity of the external acoustic signal can be generated.

According to one embodiment of the invention, the second coupling element has a sleeve which surrounds the magnetorheological or the electrorheological material. Furthermore, this sleeve can be elastic so that it can adapt to the shape of the magnetic torheological or electrorheological material. The casing can thus react to any deformations caused by the drive and, if necessary, adapt without the second coupling element losing its properties.

According to one embodiment of the invention, the first coupling element consists of a damping material. The drive can thus be supported in relation to the inner membrane surface. The damping material can be a plastic or a

Be a foam structure that can dampen vibration.

Alternatively or additionally, the first coupling element can also have a magnetorheological or an electrorheological material which can be stiffened in a targeted manner.

According to one embodiment of the invention, the electrical signal has a DC voltage component and an AC voltage component. The AC voltage component corresponds to the acoustic signal and the DC voltage component is set up to specifically stiffen the second coupling element. The DC component can stiffen a magnetorheological material via an emerging magnetic field. Alternatively or additionally, the direct component can also be introduced directly into the second coupling element through an electrical connection if the latter has an electrorheological material.

According to one embodiment of the invention, the drive has a coil former and a coil core, so that an electromagnet is created. The coil former radially surrounds the coil core and the coil former is set up to move the coil core axially by means of a magnetic field. The first coupling element is attached to the coil body. The control unit is set up to apply the electrical signal to the coil former, which causes the coil core to vibrate the inner membrane surface, which is connected to a first end of the coil core, so that the acoustic signal from the inner membrane surface is emitted. A second end of the coil core is connected to the second coupling element. The control unit is also set up to specifically stiffen the second coupling element, so that the coil core, if necessary, sets the outer membrane surface in vibration, so that the acoustic signal is emitted from the outer membrane surface.

In other words, the drive can have an electromagnet. This can consist of a coil former and a magnetic coil core, for example made of soft iron. The coil body can enclose the coil core and when a current flows through the coil a magnetic field can be built up or generated which causes the coil core to move axially within the coil body. If there are rapid changes between the polarities of the current, the coil core in the coil body begins to oscillate accordingly. These vibrations can be transferred to a membrane surface so that it emits an acoustic signal. A first end of the coil core can be firmly connected to the inner membrane surface and excite it to vibrate. A second end of the coil core can be connected to the wide coupling element, which in turn can be connected to the outer membrane surface. In the first state, in which the second coupling element is not stiffened, it can dampen the vibrations of the coil core. The vibrations are therefore not transmitted to the outer membrane surface. In the second state, in which the second coupling element is stiffened, it can transmit the vibrations of the coil core to the outer membrane surface, so that it is also excited to vibrate and emit the acoustic signal.

According to one embodiment of the invention, the inner membrane surface and / or the outer membrane surface is a sheet metal part of a vehicle. Alternatively or additionally, the inner or the outer membrane surface can also be a plastic part or a glass part. However, it should be understood that two different membrane surfaces can be excited to vibrate by the drive, at least one membrane surface being switchable.

According to one embodiment of the invention, the first coupling element surrounds the coil core in a ring. It should be noted that the first coupling element can also connect the inner membrane surface and the drive or the coil former at only a few points.

Another aspect of the invention relates to a vehicle with a switchable described above and below

Sound actuator.

The vehicle is, for example, a

Motor vehicle, such as car, bus or truck, or else a rail vehicle, a ship, or an airplane or a helicopter.

Further features, advantages and possible uses of the invention result from the following description of the exemplary embodiments and the figures.

The figures are schematic and not to scale. If the same reference numerals are given in the following description of the figures, they denote the same or similar elements.

Fig. 1 shows a sectional view of a switchable Schallak tuators with a switchable second coupling element according to an embodiment of the invention.

Fig. 2 shows a sectional view of a switchable Schallak tuators with a switchable second coupling element (not stiffened) and a coil according to an embodiment of the invention.

Fig. 3 shows a sectional view of a switchable Schallak tuators with a switchable second coupling element (stiffened ver) and a coil according to an embodiment of the invention.

Fig. 4 shows a block diagram for a switchable

Sound actuator according to an embodiment of the invention.

5 shows a voltage signal for controlling a switchable sound actuator according to an embodiment of the invention.

Fig. 6 shows a DC voltage and an AC voltage source for generating an electrical signal according to one Embodiment of the invention.

7 shows a vehicle with a switchable sound actuator according to an embodiment of the invention.

Fig. 1 shows a sectional view of a switchable Schallak tuators 1. This sound actuator 1 has a first coupling element 20, a second coupling element 30 and a drive 10. It can also be seen that the sound actuator is arranged between two membrane surfaces 21, 31. An inner membrane surface 21 is shown above and an outer membrane surface 31 is shown below. The switchable sound actuator 1 can either specifically excite only the inner membrane surface 21 or the inner and outer membrane surface 21, 31 so that they emit an acoustic signal. The drive 10 has a first end 10a and a second end 10b. The first end 10a faces the inner membrane surface 21 and is connected to it, for example glued, welded or screwed. Thus, the drive 10 can excite the inner membrane surface 21 to vibrate, as a result of which the inner membrane surface 21 emits the acoustic signal. Furthermore, the first coupling element 20 is arranged between the drive 10 and the inner membrane surface 21 and serves to hold the drive 10. The first coupling element 20 can consist of an elastic material, such as a plastic or a foam. The second end 10b of the drive 10 faces the outer membrane surface 31 and is connected to it by means of the second coupling element 30. The second coupling element 30 has a material with a variable stiffness, so that the second coupling element 30 can be stiffened in a targeted manner. Is the second Kop pelelement 30 stiffened, for example by an applied electrical or magnetic field, the drive 10 can also excite the outer membrane surface 31 via the second coupling element 30 to vibrate, so that the outer membrane surface 31, the acoustic Signal emits. It should be noted that if the second coupling element 30 is not stiffened, it dampens the vibrations from the drive 10 and does not transmit it to the outer membrane surface. The second coupling element 30 can have, for example, a magnetorheological or an electrorheological material, for example a liquid in a shell. The dashed line represents the movement axis 13 of the drive 10 and the inner membrane surface 21, which can oscillate by the amount x. In the embodiment from FIG. 1, the second coupling element 30 is not stiffened, so that only the inner membrane surface 21 is excited to vibrate.

2 also shows the switchable sound actuator 1. The drive 10 here has a coil former 12 and a magnetic coil core 11, for example soft iron. The coil body 12 encloses the coil core 11. Furthermore, the coil body 12 has an electrical conductor with a plurality of turns, so that when an electrical current flows through it, it builds up a magnetic field. This magnetic field can move the coil core 11 along the movement axis 13 and excite vibrations. The coil core 11 can transmit these vibrations to the inner membrane surface 21 and optionally to the outer membrane surface. It can also be seen that the first coupling element 20 is arranged between the coil former 12 and the inner membrane surface. Thus, the first coupling element 20 supports the coil body 12. In this case, the first coupling element 20 can surround the coil core 11 in a ring shape or can rest against fixed contact points, for example two. Furthermore, it can be seen that the second coupling element 30 extends beyond the second end of the drive 10. However, it should be noted that the second coupling element 30 can also be arranged only partially between the coil core 11 and the outer membrane surface 31. In the state shown in FIG. 2, the second coupling element 30 is not stiffened and thus dampens the second coupling element 30, the vibrations of the Spu steering core 11 and the outer membrane surface 31 is not excited to vibrate. An alternating voltage signal is applied to the coil former 12. This AC voltage signal corresponds to the acoustic signal.

It should be noted that a magnetorheological material should have a certain inertia, so that the second coupling element 30 is not constantly stiffened and liquefied again by the changing magnetic field of the coil.

3 also shows the switchable sound actuator 1. In this case, however, the second coupling element 30 has been stiffened, so that the vibrations of the coil core 11 are transmitted to the inner 21 and the outer membrane surface 31 (represented by the two arrows with x). So that the second coupling element 30 can be stiffened, the coil body is acted upon by an electrical signal which, in addition to the AC voltage component, also has a DC voltage component. This DC voltage component deflects the coil core 11 in the direction of the outer membrane surface 31, as a result of which the first coupling element 20 is compressed. Furthermore, the second end of the coil core 11 now projects into the second coupling element 30 and can change the stiffness or the viscosity of the magnetorheological material in the second coupling element 30 due to the magnetic field, as a result of which the coil core 11 can also excite the outer membrane surface 31 to vibrate and thus the outer membrane surface 31 emits the acoustic signal.

FIG. 4 shows a block diagram of the switchable sound actuator 1. This has a control unit 40 and a drive 10. This drive 10 can in particular be an electromagnet. The control unit 40 can selectively apply an electrical signal to the drive 10 so that it has an internal signal Vibrated membrane surface or an inner and an outer membrane surface, so that an acoustic signal is emitted by this.

5 shows a diagram of an electrical signal 50 with which the switchable sound actuator is acted upon. The time in seconds is plotted on the abscissa and the voltage in volts on the ordinate. Furthermore, the DC voltage component 52 of the electrical signal 50 is shown. The AC voltage component is added to the DC voltage component 52, so that the electrical signal 50 shown arises. It should be noted that the AC voltage component corresponds to the acoustic signal which is to be output via the switchable sound actuator. The

DC voltage component 52 is used for the targeted switching between the inner membrane surface and the inner and outer membrane surface. In the electrical signal shown, the second coupling element is stiffened, so that the outer membrane surface is also excited to vibrate and emits the acoustic signal.

Fig. 6 shows an AC voltage source 61 and a DC voltage source 62 for generating an electrical signal, which is then amplified by an amplifier 60, so that the electrical signal 50 is generated to control the switchable sound actuator. The control unit 40 can control both voltage sources 61, 62 in a targeted manner. The voltages of the DC voltage source 62 and the AC voltage source 61 are added, so that the subsequent electrical signal has a DC voltage component and an AC voltage component. The AC voltage source 61 provides a voltage corresponding to the acoustic signal. This alternating voltage can cause the coil of the switchable sound generator to vibrate the inner membrane surface or the inner and outer membrane surfaces. The DC voltage source 62 provides the voltage, for example 10 V, for the specific stiffening of the second coupling element.

FIG. 7 shows a vehicle 2 with a switchable sound actuator 1. This sound actuator 1 can in particular be arranged between an outer and an inner sheet metal or plastic part of this vehicle 2, so that a specific switch is made between an inner acoustic signal and an inner and outer acoustic signal can be. In other words, either only an interior of the vehicle 2 or the interior and the exterior of the vehicle can be subjected to an acoustic signal. So there is no need for an additional one

Sound actuator for the outside area of the vehicle 2 are installed, but the outside area can be selectively switched on by the switchable sound actuator 1. Weight, installation space and costs can thus be saved.

Claims

1. Switchable sound actuator (1), comprising:

- a first coupling element (20);

- A second coupling element (30);

- A drive (10); and

- a control unit (40),

wherein the first coupling element (20) is fastened to the drive (10) and the first coupling element (20) is set up to be connected to an inner membrane surface (21),

the control unit (40) being set up to apply an electrical signal (50), which corresponds to an acoustic signal, to the drive (10), which causes the drive (10) to move the inner diaphragm surface (21), which is connected to a first end (10a) of the drive (10) to vibrate so that the acoustic signal is emitted from the inner membrane surface (21),

wherein the second coupling element (30) is set up to be connected to an outer membrane surface (31),

a second end (10b) of the drive (10) being connected to the second coupling element (30),

wherein the second coupling element (30) has a material with a variable stiffness,

wherein the control unit (40) is set up to stiffen the second coupling element (30) in a targeted manner, so that the drive (10) vibrates the outer membrane surface (31) as required, so that the acoustic signal is emitted from the outer membrane surface (31) .

2. Sound actuator (1) according to claim 1,

wherein the second coupling element (30) has a magnetorheological or an electrorheological material, at which can be influenced by a magnetic or an electrical field, the rigidity.

3. sound actuator (1) according to claim 1 or 2,

the magnetorheological or the electrorheological material being a liquid.

4. Sound actuator (1) according to claim 2 or 3,

wherein the second coupling element (30) has a sleeve which surrounds the magnetorheological or the electrorheological material.

5. Sound actuator (1) according to one of the preceding claims,

wherein the first coupling element (20) consists of a damping material.

6. sound actuator (1) according to one of the preceding claims,

wherein the electrical signal (50) has a DC voltage component (52) and an AC voltage component, the AC voltage component corresponding to the acoustic signal,

wherein the DC voltage component (52) is set up to specifically stiffen the second coupling element (30).

7. sound actuator (1) according to one of the preceding claims,

the drive (10) having a coil former (12) and a coil core (11),

wherein the coil former (12) radially surrounds the coil core (11) and wherein the coil former (12) is set up to move the coil core (11) axially by a magnetic field, the first coupling element (20) being fastened to the coil former (12),

wherein the control unit (40) is arranged to strike the coil former (12) with the electrical signal (50), which causes the coil core (11) to contact the inner membrane surface (21), which is connected to a first end of the coil core is connected to vibrate so that the acoustic signal is emitted from the inner membrane surface (21),

a second end of the coil core (11) being connected to the second coupling element (30),

the control unit (40) being set up to specifically stiffen the second coupling element (30), so that the coil core (11) vibrates the outer membrane surface (31) as required, so that the acoustic signal is emitted from the outer membrane surface (31) .

8. sound actuator (1) according to one of the preceding claims,

wherein the inner membrane surface (21) and / or the outer membrane surface (31) is a sheet metal part of a vehicle (2).

9. sound actuator (1) according to claim 7,

wherein the first coupling element (20) surrounds the coil core (11) in a ring.

10. Vehicle (2) with a switchable sound actuator (1) according to one of the preceding claims.