Sound actuator

Abstract

The invention relates to a sound actuator (10) having a magnet arrangement (26) and an electric drive device (38) for the magnet arrangement (26), wherein the drive device (38) has at least one coil (50) having a first current connection (52) and a second current connection (54), wherein the magnet arrangement (26) can be excited to vibrate in a vibration direction (34) by a current flowing through the coil (50). The drive device (38) has at least one printed circuit board (48) on which the coil (50) and the first current connection (52) and the second current connection (54) are mounted, wherein the at least one coil (50) is in the form of a conductor track coil (50) and wherein the plane of the printed circuit board (48) extends in particular in the vibration direction (34).

Description

[0001] Description

[0002] Sound actuator

[0003] The invention relates to a sound actuator with a magnet arrangement and an electric drive device for the magnet arrangement, wherein the drive device has at least one coil with a first current connection and a second current connection, wherein a current flowing through the coil can excite the magnet arrangement to oscillate in one oscillation direction.

[0004] Actuators, in particular acoustic actuators or sound actuators, are known from the prior art, with which acoustic signals, for example tones, noises or vibrations, can be transmitted to components, in particular in a vehicle.

[0005] Such actuators comprise, for example, a drive device with a coil through which a current can flow, as well as a magnet arrangement that is mounted for limited movement relative to the coil and can be excited to movement, in particular to vibrations, by energizing the coil. The coil arrangement and the magnet arrangement can be installed in the housing as a prefabricated actuator unit or fixed therein. Such a sound actuator is shown, for example, in DE 10 2021 210 561 A1. The coil of such sound actuators is usually wound and arranged between two cover plates that serve as coil supports. However, manufacturing, in particular attaching the coil to the coil supports, is very complex.

[0006] The object of the invention is to provide a sound actuator that is simpler and more cost-effective to manufacture.

[0007] To achieve this objective, a sound actuator is provided with a magnet arrangement and an electric drive device for the magnet arrangement, wherein the drive device has at least one coil with a first current connection and a second current connection, wherein a current flowing through the coil can excite the magnet arrangement to oscillate in a direction of oscillation. The drive device has at least one printed circuit board on which the coil and the first current connection and the second current connection are mounted, wherein the at least one coil is designed as a conductor track coil, and wherein the plane of the printed circuit board runs in particular in the direction of oscillation.

[0008] According to the invention, the coil is therefore not wound and arranged between two coil supports, but applied as a conductor track to a circuit board, for example, printed. This significantly reduces the number of individual parts for assembling the sound actuator, allowing for simple and quick assembly of the sound actuator. In addition, printing the conductor track enables simple and quick production and adaptation of the at least one coil and thus the drive device, for example to different manufacturer requirements. In particular, the design of the at least one conductor track that forms the coil can be varied as desired without, for example, requiring different coil supports.

[0009] The sound actuator preferably has a frame in which the magnet arrangement is mounted so as to be movable, in particular resiliently, in the direction of vibration, wherein the drive device is fixed in the frame in the direction of vibration. The drive device is rigidly held in the frame and excites the magnet arrangement to vibrate via the current flowing through the at least one coil. In particular, spring elements can be provided in the frame, which are supported on the frame and / or an optional housing and hold the magnet arrangement in a basic position from which the magnet arrangement is deflected by excitation by the coil. The frame enables simple and reliable mounting or guidance of the magnet arrangement in the direction of vibration. Furthermore, simple fixing and alignment of the drive device relative to the magnet arrangement of the drive device is possible.Furthermore, the fixed drive unit enables simple and reliable contacting and power supply to the circuit board and coil. In particular, the assembly, consisting of the frame, the magnet assembly, and the drive unit, can be pre-assembled for installation in a housing, for example.

[0010] For example, the magnet arrangement has an air gap extending in the direction of oscillation, in which the drive device is arranged. The air gap is preferably designed so that the drive device is arranged as close as possible to the magnet arrangement, but the magnet arrangement can move freely relative to the drive device. This allows for very direct control and excitation of the magnet arrangement.

[0011] The magnet arrangement is preferably symmetrical, in particular mirror-symmetrical, with respect to a plane of symmetry running through the air gap. The magnet arrangement comprises, in particular, a plurality of magnets arranged symmetrically, in particular symmetrically in pairs, with respect to the plane of symmetry. In particular, the drive device, in particular the at least one coil, is arranged such that the resultant of the force on the magnet arrangement lies in the plane of symmetry, i.e., a central force is introduced onto the magnet arrangement. Undesired lateral movement of the magnet arrangement and the resulting unwanted noise can thus be prevented. In particular, the coil can run in the plane of symmetry.

[0012] The sound actuator can have a housing, wherein the magnet assembly is mounted within the housing so as to be movable, in particular spring-mounted, in the direction of vibration, and the drive device is fixed in the housing in the direction of vibration. The housing can be sealed in a watertight and / or dusttight manner to protect the magnet assembly and the drive device from external influences. Furthermore, the housing can provide a sound radiation surface, which either provides sound radiation itself or can be connected to a component of the vehicle to which the sound is to be transmitted.

[0013] In principle, only one circuit board is required, on which only one coil must be provided. Optionally, the sound actuator can also have multiple circuit boards, with each circuit board containing at least one coil with at least one first power connection and one second power connection. The circuit boards and coils can, in particular, be designed and arranged to ensure ideal excitation of the magnet arrangement. For example, multiple circuit boards and coils can provide more differentiated excitation of the magnet arrangement, or a more uniform force application, for example, to prevent imbalance or lateral movement of the magnet arrangement.

[0014] In particular, the magnet arrangement can also have a plurality of air gaps, each of which contains at least one printed circuit board. The number of printed circuit boards and thus the type of excitation of the magnet arrangement can depend in particular on the size of the magnet arrangement and / or the desired vibration excitation of the magnet arrangement.

[0015] Furthermore, multiple coils can be provided on a circuit board. The number and shape of the coils can depend on the desired type of excitation of the magnet arrangement. In particular, the coils can overlap or, for example, spiral into each other. The circuit boards can each have separate power connections to control them individually, or they can share common first and second power connections. In particular, the power supply to the individual coils of a circuit board can also be provided via switches or other electrical or electronic components.

[0016] For example, at least one coil can be provided on a first surface of the circuit board and on a second surface of the circuit board opposite the first surface. This means that the circuit board has at least one coil on each side, allowing the best possible utilization of the circuit board surface.

[0017] Regardless of whether the coils are provided on a common circuit board, on different circuit boards, or on different sides of a circuit board, at least two coils of the drive device can be arranged electrically in series and / or at least two coils can be arranged electrically in parallel. These can also be provided on different circuit boards and / or on different sides of a circuit board. The power supply of the individual coils can be controlled via switches or other electrical or electronic components.

[0018] For example, the coils can be designed to overlap perpendicular to the plane of the circuit boards.

[0019] The coils can differ in shape, thickness of the conductor tracks and / or other characteristics, whereby these can be selected in such a way that an ideal vibration excitation of the magnet arrangement is ensured.

[0020] Preferably, the coils are electrically insulated from each other so that they can be supplied with power completely independently and can thus be controlled individually for the vibration excitation of the magnet arrangement.

[0021] For example, a coating, in particular a varnish or a resin, which electrically insulates the at least one coil is provided on the at least one printed circuit board. For example, the varnish is coated with the varnish after the conductor tracks have been produced and the circuit board has optionally been populated with further electrical or electronic components. The varnish can thus provide additional protection for the circuit board from external influences. The varnish is preferably thicker than the height of the conductor tracks that form the coil, thus ensuring reliable insulation. For example, the thickness of the conductor tracks of the coil is between 25 μm and 500 μm, in particular between 35 μm and 400 μm.

[0022] Furthermore, additional heat dissipation elements can be provided on the at least one circuit board to dissipate the heat generated on the circuit board. The heat dissipation elements, particularly in the plane of the circuit board, enclose at least one coil, at least in sections. For example, the heat conduction elements surround the coil in a frame-like manner.

[0023] The heat dissipation elements and the coil conductors can be made of the same material, with the heat dissipation elements being insulated from the coil conductors. This can simplify the production of the circuit board, as the heat dissipation elements can be manufactured in a single process step with the coils.

[0024] Further electrical and / or electronic components, in particular sensors, control devices and / or communication devices, may be provided on at least one printed circuit board.

[0025] The conductor tracks are preferably made of a metal, a metal alloy or another electrically conductive material, for example of an electrically conductive plastic. In particular, the conductor tracks can consist of copper, although alternatively aluminum, iron or another conductive material can also be used.

[0026] The circuit board can be made of plastic, preferably fiber-reinforced plastic, hard paper or another suitable material.

[0027] Further advantages and features can be found in the following description in conjunction with the attached drawings. These show:

[0028] Figure 1 shows a sound actuator from the prior art; Figure 2 shows a detailed view of the sound actuator from Figure 1;

[0029] Figures 3a and 3b Detailed view of the drive device of the sound actuator from Figures 1 and 2;

[0030] Figure 4 is a schematic view of a drive device according to the invention for the sound actuator from Figures 1 and 2;

[0031] Figure 5 shows a second embodiment of a drive device of a

[0032] Drive device for the sound actuator from Figures 1 and 2;

[0033] Figure 6 shows a third embodiment of a drive device of a

[0034] Drive device for the sound actuator from Figures 1 and 2;

[0035] Figure 7 shows a detailed view of a drive device from Figures 4 to 6;

[0036] Figure 8 shows a fourth embodiment of a drive device of a

[0037] Drive device for the sound actuator from Figures 1 and 2;

[0038] Figure 9 shows a fifth embodiment of a drive device of a

[0039] Drive device for the sound actuator from Figures 1 and 2;

[0040] Figure 10 shows a sixth embodiment of a drive device of a

[0041] Drive device for the sound actuator from Figures 1 and 2; and

[0042] Figure 11 shows a seventh embodiment of a drive device of a

[0043] Drive device for the sound actuator from Figures 1 and 2.

[0044] Figures 1 and 2 show a sound actuator 10, particularly for use in a vehicle. The sound actuator 10 can generate sound waves and transmit them, for example, to other components within the vehicle so that they are acoustically perceptible to vehicle occupants. The sound actuator has a housing 12 with a first housing half 14 and a second housing half 16, in which an actuator unit 18 is fixed. The housing halves 14, 16 are preferably made of plastic, for example ABS, PBT, PET, PLA; PA, PS), particularly preferably of a fiber-reinforced plastic, for example glass fiber or carbon fiber.

[0045] As can be seen in Figure 2, the actuator unit 18 has a frame 20 in which a magnet arrangement 26 consisting of a plurality of magnet plates 22 and pole plates 24 is arranged, each of which provides a permanent magnetic field. In the embodiment shown here, the magnet arrangement 26 has two packages 28 with magnet plates 22 and pole plates 24, which are arranged mirror-inverted with respect to a plane of symmetry 30, with an air gap 32 provided between the packages 28. The magnetic orientation of the two packages 28 is inverted with respect to the plane of symmetry 30, so that the magnetic flux in the upper region and lower region of the air gap 32 is oriented in opposite directions (Figure 1).

[0046] The magnet arrangement 26 is mounted in the frame 20 so as to be movable to a limited extent in a direction of oscillation 34, wherein spring elements 30 are provided which limit the movement and hold the magnet arrangement 26 in a rest position.

[0047] The magnetic plates 22 and the pole plates 24 are made of ferromagnetic material and can have a constant thickness, but are preferably thicker on the side facing the air gap 32 than on the side facing away from the air gap. The transition between the thicker and thinner regions of the magnetic plates 22 and the pole plates 24 can be configured, for example, to be linear, sinusoidal, or parabolic in some sections. Furthermore, a collar of constant thickness of up to 50% of the respective extent of the magnetic plates 22 and the pole plates 24 can be formed on both the side facing the air gap 32 and the side facing away from the air gap 32. The actuator unit 18 further comprises a drive device 38 with a coil 40 designed as an excitation coil (see also Figures 3a and 3b).The drive device 32 is arranged in an air gap 32 between the magnet assembly 26 and extends in the direction of oscillation 28. By energizing the coil 34, the magnet assembly 26 can be excited to oscillate in the direction of oscillation 34. These oscillations are transmitted via the coil frame 20 to the housing 12 and thus to other components.

[0048] As can be seen particularly in Figures 3a and 3b, the windings of the current-carrying coil 40 are located in the plane of symmetry 30 and are essentially rectangular. The coil 40 is wound around a core 42 made of non-ferromagnetic material in order to keep the coil's self-inductance low and thus ensure strong vibration excitation even at high frequencies. The core 42 of the coil 40 is preferably made of a material with good thermal conductivity properties, for example aluminum or copper, in order to ensure the best possible heat dissipation from the coil. The aspect ratio of the rectangular coil is designed such that its longer extension, running parallel to the pole plate edge, is at least twice its height.

[0049] The arrangement of the coil 40 is on the plane of symmetry 30 between the magnetic plates 22 and the pole plates 24, so that the longer side of the coil is positioned essentially centrally with respect to the magnetic arrangement 26 in all spatial directions.

[0050] The coil 40 has a structure symmetrical to the plane of symmetry 30. The coil 40 wound around the core 42 is covered laterally by cover plates 44, which completely cover the coil 40 laterally. Optionally, the coil 40 is covered on its top and bottom sides by additional cover bars 46. The cover plates 44 and the cover bars 46 are preferably made of a non-ferromagnetic material with good thermal conductivity properties, such as aluminum, copper, or some plastics. Due to the described arrangement of the coil 40 in the magnetic flux, the electrical flux in the longer coil sections runs essentially orthogonal to the respective magnetic fluxes, resulting in a force excitation proportional to the electrical excitation of the coil 40, which in turn acts orthogonally to the magnetic flux and the electrical flux.

[0051] Figure 4 shows an alternative drive device for the sound actuator 10 shown in Figures 1 and 2. Instead of the wound coil 40 and the cover plates 44, a printed circuit board 48 is used, on which a coil formed as a conductor track coil 50 is used. The coil 40 is therefore not wound, but applied directly to the printed circuit board 48 or formed thereon.

[0052] Furthermore, the conductor track coil 50 has a first power connection 52 and a second power connection 54 for making power contacts. The power connections 52, 54 are provided here at the beginning and end of the conductor track coil, respectively. However, it is also possible to provide them at other positions on the circuit board 48, which allow easier contact with a power supply 50. The power connections 52, 54 can, for example, be formed as a conductor track on the circuit board 48.

[0053] The windings of the conductor track coil 50 are formed in the plane of the circuit board, i.e., the conductor track coil 50 is formed spirally on the circuit board 48. In the embodiment shown here, the conductor track coil is rectangular, although it can optionally also have rounded corners. In particular, the number of windings and the thickness of the conductor track can also be adapted and is not limited to the embodiments shown in the examples.

[0054] In principle, the shape of the conductor track can be adapted as desired, for example, to the installation conditions, the shape of the sonic actuator 10, or the desired vibration excitation. The variants described for Figures 1 to 3b regarding the design of the coil 40 also apply, to the extent feasible, to the conductor track coils 50 described in Figure 4 and the following figures.

[0055] The electrically conductive tracks 56 of the conductor track coil 50 have a thickness 58 between 25 pm and 500 pm, preferably between 35 pm and 400 pm (see Figure 7). The width 60 of the electrically conductive tracks 56, together with the thickness 58, determines the conductor cross-section, from which the specific electrical resistance of the electrically conductive tracks 56 is derived, which can thus be specifically adjusted.

[0056] Optionally, the electrically conductive tracks 56 can be coated with an electrically insulating coating 62, for example a lacquer or a resin, in order to avoid electrical short circuits with adjacent components.

[0057] Further electrical and electronic components 64 and sensors 66 can be mounted on or incorporated into the circuit board 48, in particular on and / or into the circuit board coil 50. The sensors 66 can be, for example, acceleration sensors, pressure sensors, strain gauges, or temperature sensors. Furthermore, active electronic components such as audio amplifier circuits, radio receivers / transmitters, for example for wireless communication, or digital signal processors can be mounted on or incorporated into the circuit board coil 40 as electrical or electronic components 64. This enables, for example, active and smart sound actuators. Contacting can be established independently or via the power connections 52, 54 of the circuit board coil 50.

[0058] The printed circuit board coil 50 can be manufactured conventionally, for example, by UV light exposure, etching, or printing. For printed coils, electrically conductive materials can be printed directly onto carrier materials. The printed circuit board 48 can be made of, for example, plastics, laminated paper, or preferably fiber-reinforced plastics.

[0059] The electrically conductive tracks 56 are preferably made of metals, particularly preferably copper. Alternatively, aluminum, iron, or electrically conductive plastics are possible materials.

[0060] On each level of the circuit board 48, several spiral-shaped conductor tracks 56 can be arranged side by side or nested within one another, each forming a conductor track coil 50. The conductor track coils 50 can be electrically connected in series and / or parallel.

[0061] Figure 5 shows a drive device in which two essentially square conductor track coils 50 are arranged side by side, with the conductor track coils 50 each having separate first power connections 52 and second power connections 54. The power connections 52, 54 can also be jointly connected to a power supply. Optionally, switches can be provided to control the power supply to the individual conductor track coils 50, so that the conductor track coils 50 can be supplied with power separately or jointly.

[0062] In Figure 6, two conductor track coils 50 are arranged spirally one inside the other, with these conductor track coils 50 each having separate first power connections 52 and second power connections 54. In this embodiment, too, the coils can be supplied with power separately or together.

[0063] In the embodiments described above, conductor track coils 50 are provided on only one side of the circuit board 48. Optionally, however, electrically conductive tracks 56, i.e., conductor track coils 50, can also be provided on both sides of the circuit board 48, i.e., on a front side and a rear side of the front. The conductor track coils 50 arranged on the two sides can be completely coupled or coupled to one another, for example, electrically contacted. Figure 8 shows a drive device 38 in which conductor track coils 50 are shown on both sides of the circuit board 48. The conductor track coil 50 arranged on the rear side with respect to the plane of the drawing is represented here by a dashed line.The first power terminal 52 of the rear-side conductor coil 50 is connected to the second power terminal of the front-side conductor coil 50 via a via 68, so that the conductor coils 50 are electrically arranged in series. The electrically conductive paths 56 of the two conductor coils 50 are arranged such that the flow direction 70 of the electrical current through the respective conductor coils 50 runs in the same direction.

[0064] Optionally, the two conductor track coils can also be designed electrically separately from each other so that they can be controlled separately.

[0065] The drive device 38 can also comprise a plurality of circuit boards 48, which can be mechanically and / or electrically connected to one another (see Figure 9). At least one electrically conductive track 56 can be provided on each of the circuit boards 48, forming a conductor track coil 50. The above statements apply analogously to the design of the individual conductor track coils 50 on the circuit boards 48.

[0066] The electrically conductive tracks 56 of the individual circuit boards 48 can have separate power connections 52, 54 and can be arranged electrically parallel and / or in series with one another. In particular, an electrical connection of individual conductor track coils 50 via a through-hole 68, as described in Figure 8, is also possible.

[0067] The electrically conductive paths on the individual circuit boards 48 are preferably arranged such that the flow direction 70 of the electrical current of the individual conductor track coils 50 points in the same direction in sections. The number of circuit boards 48 can be between 2 and 20. The individual circuit boards 48 of such a circuit board arrangement 48 can also be equipped with circuit board coils 50 on both sides.

[0068] In Figure 10, a heat dissipation element 72 with high thermal conductivity is additionally provided to improve heat dissipation from the circuit board 48, in particular from the circuit board coil 50. In the embodiment shown here, the heat dissipation element 72 encloses the electrically conductive track 45 in the plane of the circuit board, at least in sections, in a frame-like manner.

[0069] The heat dissipation element 72 can, for example, be made of the same material as the electrically conductive tracks 56, wherein the heat dissipation element 72 is electrically insulated from the electrically conductive tracks 56, for example, by a non-conductive gap 74 or by an insulating coating 62. In the embodiment shown here, the heat dissipation element 72 is preferably designed with a large surface area to improve heat dissipation. To minimize losses due to eddy currents, one or more interruptions can be inserted into the heat dissipation element 72 in the circumferential direction, interrupting the electrical current flow of any induced eddy currents.

[0070] The heat dissipation element 72 can also be formed by an additional layer with high thermal conductivity on the front or back of the circuit board 48 or between the individual circuit boards 48. In principle, it must also be ensured here that there is no electrical contact between the electrically conductive tracks 56 and the heat dissipation element 72.

[0071] List of reference symbols Sound actuator 46 Cover bar Housing 48 Printed circuit board First housing half 50 Conductor track coil Second housing half 25 52 First power connection Actuator unit 54 Second power connection Frame 56 Electrically conductive track Magnetic plates 58 Thickness of the electrically conductive pole plates Track Magnet arrangement 30 60 Height of the electrically conductive packages of magnetic plates and track Pole plates 62 Insulating coating Plane of symmetry 64 Electrical or electronic Air gap Components Direction of vibration 35 66 Sensors Springs 68 Through-hole drive device 70 Direction of flow Coil 72 Heat dissipation element Core of the coil 74 Non-conductive gap Cover plates

Claims

Patent claims 1. Sound actuator (10) with a magnet arrangement (26) and an electrical Drive device (38) for the magnet arrangement (26), wherein the drive device (38) has at least one coil (50) with a first current connection (52) and a second current connection (54), wherein the magnet arrangement (26) can be excited to oscillate in a direction of oscillation (34) by a current flowing through the coil (50), characterized in that the Drive device (38) has at least one printed circuit board (48) on which the coil (50) and the first current connection (52) and the second current connection (54) are applied, wherein the at least one coil (50) is designed as a conductor track coil (50) and wherein the plane of the printed circuit board (48) runs in particular in the direction of oscillation (34).

2. Sound actuator according to claim 1, characterized in that the sound actuator (10) has a frame (20) in which the magnet arrangement (26) is mounted so as to be movable, in particular resilient, in the direction of vibration (34), wherein the drive device (38) is fixed in the frame (20) in the direction of vibration (34).

3. Sound actuator according to one of claims 1 and 2, characterized in that the magnet arrangement (26) has an air gap (32) extending in the direction of oscillation (34), in which the drive device (38) is arranged.

4. Sound actuator according to claim 3, characterized in that the magnet arrangement (26) is designed symmetrically, in particular mirror-symmetrically, with respect to a plane of symmetry (30) running through the air gap (32), wherein the magnet arrangement (26) in particular has a plurality of magnets arranged symmetrically, in particular symmetrically in pairs, with respect to the plane of symmetry (30).

5. Sound actuator according to one of the preceding claims, characterized in that the sound actuator (10) has a housing (12), wherein the magnet arrangement (26) is mounted in the housing (12) so as to be movable, in particular resilient, in the direction of vibration (34), and the drive device (38) is fixed in the housing (12) in the direction of vibration (34).

6. Sound actuator according to one of the preceding claims, characterized in that a plurality of printed circuit boards (48) are provided, wherein on each printed circuit board (48) at least one conductor track coil (50) and at least one first power connection (52) and one second power connection (54) are provided.

7. Sound actuator according to one of the preceding claims, characterized in that several conductor track coils (50) are provided on a printed circuit board (48).

8. Sound actuator according to claim 7, characterized in that at least one coil (50) is provided on a first surface of the circuit board (48) and a second surface of the circuit board (48) opposite the first surface.

9. Sound actuator according to one of claims 6 to 8, characterized in that at least two coils (50) are arranged electrically in series and / or at least two coils (50) are arranged electrically in parallel.

10. Sound actuator according to one of claims 6 to 9, characterized in that the coils (50) can be designed to overlap perpendicular to the plane of the circuit boards (48). 11 . Sound actuator according to one of claims 6 to 10, characterized in that the coils (50) are electrically insulated from one another.

12. Sound actuator according to one of the preceding claims, characterized in that a coating (62), in particular a lacquer, is provided on the at least one printed circuit board (48), which electrically insulates the at least one coil (50).

13. Sound actuator according to one of the preceding claims, characterized in that the thickness (58) of the electrically conductive tracks (56) of the coil (50) is between 25 pm and 500 pm, in particular between 35 pm and 400 pm.

14. Sound actuator according to one of the preceding claims, characterized in that heat dissipation elements (72) are provided on the at least one circuit board (48), wherein the heat dissipation elements (72), in particular in the plane of the circuit board (48), enclose the at least one coil (50) at least in sections.

15. Sound actuator according to claim 14, characterized in that the heat dissipating elements (72) and the electrically conductive tracks (56) of the coil (50) are made of the same material and are insulated from the coils (50).

16. Sound actuator according to one of the preceding claims, characterized in that further electrical and / or electronic components (64) are provided on at least one printed circuit board (48), in particular sensors (66), control devices and / or communication devices.

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