VIBRATION ACTUATOR FOR RIGID STRUCTURES FOR HIGH-PERFORMANCE BASS PLAYBACK IN AUTOMOBILES

Abstract

An actuator for exciting a component of a motor vehicle with vibrations. The actuator has a housing, an electrical coil and a magnet that is movable to a limited extent in the housing.

Claims

1. An actuator for exciting at least one component of a motor vehicle with vibrations, the actuator comprising: a housing which is configured to be connected to the component; an electrical coil which is rigidly connected to the housing and is configured to generate a magnetic field when an electrical current flows through the coil; and a magnet which is arranged in the housing so as to be movable to a limited extent.

2. The actuator as claimed in claim 1, wherein the actuator has at least one first pole plate which is assigned to the magnet, wherein the outwardly directed surface of a first pole plate is concave, and therefore said surface has a greater thickness at the outer edge than in its center.

3. The actuator as claimed claim 1, wherein the first pole plate has a collar along its outer edge, of substantially constant thickness, which can comprise up to 20% of the total extent of the pole plate.

4. The actuator as claimed claim 2, wherein that surface of the first pole plate which is oriented toward the magnet is substantially planar.

5. The actuator as claimed in claim 2, wherein the first and/or a second pole plate are/is configured with regard to their outwardly directed surface in such a way that they have a substantially planar partial surface and/or a plateau in their center.

6. The actuator as claimed in claim 1, wherein the housing of the actuator has a heat capacity of at least 0.08 kJ/K, in particular of at least 0.1 kJ/K.

7. The actuator as claimed in claim 1, wherein the coil has a fixed connection to the housing by an adhesive connection of thermally relatively highly conductive adhesive, wherein said adhesive has a thermal conductivity of at least 0.8 W/(m K).

8. The actuator as claimed in claim 7, wherein the layer thickness of the adhesive is a maximum of 0.3 mm.

9. The actuator as claimed in claim 1, wherein the inner surface of the housing, which is connected to the coil and/or to the coil carrier by an adhesive connection, is structured and/or profiled.

10. The actuator as claimed in claim 1 further comprising, a spring arrangement which is configured to bias the magnet into an inoperative position, wherein the spring arrangement is configured to bias the magnet in a manner returning same back to the inoperative position along every possible direction of movement.

11. The actuator as claimed in claim 10, wherein the spring arrangement has a first spring element and a second spring element, wherein the magnet is held between the first spring element and the second spring element, wherein the first spring element biases the magnet in a first direction and the second spring element biases the magnet in a second direction opposite to the first direction, wherein the first spring element has a number of spring arms for biasing the magnet, and/or the second spring element has a number of spring arms for biasing the magnet.

12. The actuator as claimed in claim 11, wherein the spring elements are formed from a composite material.

13. The actuator as claimed in claim 11, wherein the spring elements are coated with one or more plastics with relatively high damping or with relatively massive materials, in order to dampen and/or to detune the natural vibration behavior of the spring elements.

14. The actuator as claimed in claim 11, wherein the arrangement of the spring arms is configured symmetrically or, alternatively, configured asymmetrically, in order to prevent natural vibrations.

15. The actuator as claimed in claim 11, wherein the spring arms are profiled in order to further improve the rigidity and the vibration properties, wherein the profiling is implemented by at least one rib and/or at least one bead and/or at least one edge and/or at least one curvature.

16. The actuator as claimed claim 3, wherein that surface of the first pole plate which is oriented toward the magnet is substantially planar.

17. The actuator as claimed claim 2, wherein the first pole plate has a collar along its outer edge, of substantially constant thickness, which can comprise up to 20% of the total extent of the pole plate.

18. The actuator as claimed in claim 1, wherein the housing of the actuator has a heat capacity of at least 0.1 kJ/K.

19. The actuator as claimed in claim 7, wherein the layer thickness of the adhesive is less than 0.1 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Further features and advantages will be gathered by a person skilled in the art from the exemplary embodiments described below with reference to the appended drawing.

[0075] In the drawings:

[0076] FIG. 1: shows an actuator in a lateral exploded view,

[0077] FIG. 2: shows the actuator in a perspective exploded view,

[0078] FIG. 3: shows the actuator in an assembled state,

[0079] FIG. 4: shows an alternative embodiment of a spring element,

[0080] FIG. 5: shows an exemplary cross section of a pole plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0081] FIG. 1 shows an actuator 5 according to one exemplary embodiment of the invention in a lateral exploded view.

[0082] The actuator 5 has a housing 10. The housing 10 is formed by a first cover cap 12, a second cover cap 16 and a ring 14. The two cover caps 12, 16 are arranged on the outside and are composed of non-thermally conductive, non-magnetically conductive material. It should be mentioned that one or both of said two cover caps 12, 16 could, however, also be composed, for example, of thermally conductive, non-magnetically conductive material. The ring 14 is composed of thermally conductive, magnetically conductive material.

[0083] The actuator 5 has a spring arrangement 20 which is formed by a first spring element 22 and a second spring element 24. The design thereof will be discussed in more detail further below.

[0084] The actuator 5 has a coil which is formed by a coil carrier 32, a first coil section 34 and a second coil section 36. The two coil sections 34, 36 are attached here to the coil carrier 32. Electric current can flow through the coil sections 34, 36, such that a magnetic field is generated in the coil 30.

[0085] The actuator 5 has a magnet 40. The latter is formed by a magnetic central part 42 and by a first non-magnetic pole plate 44 and a second non-magnetic pole plate 46. The central part 42 is accommodated here between the two pole plates 44, 46.

[0086] Two sets of four screws 18, 19 each are used to fasten the components mentioned. Alternatively, for example, fastening by adhesive bonding, welding or riveting would also be possible.

[0087] FIG. 2 shows the actuator 5 in a perspective exploded view. It can be seen here that the first spring element 22 has a total of four spring arms 26. Accordingly, the second spring element 24 has a total of four spring arms 28.

[0088] In the assembled state, the magnet 40 is designed in such a way that the two pole plates 44, 46 directly adjoin the magnetic central part 42. The magnet 40 is then held as a whole by the two axially adjacent spring elements 22, 24. As a result, the magnet 40 is movable only in one axial direction, wherein it is biased by the spring elements 22, 24 into a central inoperative position.

[0089] As shown, the pole plates 44, 46 are designed to be curved concavely on their outwardly directed surface. This enables a particularly space-saving arrangement of the magnet 40 between the spring elements 22, 24 and allows a particularly high magnetic flux density in the edge region of the pole plates.

[0090] In the assembled state, the coil 30 surrounds the magnet 40 radially. The coil 30 here is fixedly secured in the housing 10. By application of an electrical voltage to the coil 30, the magnet 40 can be deflected out of its inoperative position, as a result of which vibrations occur. In particular, a voltage to which an audio signal is modulated can be applied here. The magnet 40 then vibrates in accordance with this audio signal and generates corresponding vibrations. The ring 14 made of magnetically conductive material is used here to provide an advantageous magnetic closure.

[0091] A first cylinder-like projection 13, which extends inward from the first cover cap 12, and a second cylindrical projection 17, which extends inward from the second cover cap 16, serve to define the axial direction along which the magnet 40 is movable.

[0092] FIG. 3 shows the actuator 5 in the assembled state. It can be seen here that three cylindrical contact points 7 are arranged on the outside of the first cover cap 12. With said contact points, the actuator 5 can adjoin a component of a motor vehicle. Furthermore, a bore 8 in which a thread is formed is arranged in the center. The actuator 5 can thus be fastened to a component. The second cover cap 16 is also configured accordingly.

[0093] By fastening or application of the actuator 5 by bore 8 to a component of a motor vehicle, the vibrations already mentioned further above, which the magnet 40 can generate, can be transmitted to the component. In this way, the component itself can be excited to vibrate, which leads to it emitting sound waves. These sound waves can typically be heard in the interior of a vehicle. In this way, sound can be generated without the provision of a separate loudspeaker, which is particularly appropriate at low frequencies and leads to a significant saving on space and weight.

[0094] It should be mentioned that, for example, the bore 8 can also be used to connect the actuator 5 to a rigid component, such as, for example, a body part of a vehicle, and the actuator 5 can be connected on the opposite side to a component which is to be excited into vibrating. In this way, the stationary component, such as, for example, a body of the vehicle, can serve as a reference, relative to which the vibrations are excited.

[0095] FIG. 4 shows an alternative embodiment of a spring element, here by way of example the first spring element 22. This can be used in the context of the embodiment described with reference to FIGS. 1 to 3 instead of the first spring element 22 shown there and/or instead of the second spring element 24 shown there.

[0096] In contrast to the star-shaped design which can be seen in FIG. 2, the spring arms 26 of the spring element 22 illustrated in FIG. 4 are designed in a spiral shape. A different spring characteristic can thus be achieved.

[0097] FIG. 5 shows schematically an exemplary pole plate 44, 46 in cross section. The pole plate is, by way of example, configured to be substantially planar 61 on the side facing the magnet (not illustrated). The outer side or surface 62 facing away from the magnet is concave and thus the entire cross section of the pole plate is concave. The outer side has a collar 63 on the circumferential edge, at which collar the pole plate has a greater thickness or material thickness than in the center. The pole plate has a substantially planar plateau 64 in the region of the center of the outer side. The transition 65 between collar 63 and plateau 64 can be designed in various ways; a linear transition, a circular-arc-shaped transition and a parabolic transition are illustrated on the left-hand side by way of example.

[0098] If it is found in the course of the proceedings that a feature or a group of features is not absolutely necessary, then the applicant aspires right now to a wording of at least one independent claim that no longer has the feature or the group of features. This may be, for example, a subcombination of a claim present on the filing date or a subcombination of a claim present on the filing date that is restricted by further features. Claims or combinations of features of this kind requiring rewording are intended to be understood as also covered by the disclosure of this application.

[0099] It should also be pointed out that refinements, features and variants of aspects of the invention which are described in the various embodiments or exemplary embodiments and/or shown in the figures can be combined with one another in any desired manner. Single or multiple features are interchangeable with one another in any desired manner. Combinations of features arising therefrom are intended to be understood as also covered by the disclosure of this application.

[0100] Back-references in dependent claims are not intended to be understood as a relinquishment of the attainment of independent substantive protection for the features of the back-referenced dependent claims. These features may also be combined with other features in any desired manner.

[0101] Features which are only disclosed in the description or features which are only disclosed in the description or in a claim in conjunction with other features may in principle be of independent significance essential to aspects of the invention. They may therefore also be individually included in claims for the purpose of delimitation from the prior art.