Low-Profile Panel Assembly for Providing Sound Within a Passenger Compartment of a Vehicle

Abstract

A low-profile panel assembly configured to provide sound having at least one acoustic wavelength within a passenger compartment of a vehicle is provided. The vehicle has a support structure. The assembly includes a substrate panel perforated with at least one sub-wavelength hole which extends between front and back surfaces of the panel. The panel is configured to be attached to the support structure. A continuous membrane of facing material overlies and is in contact with the panel. The membrane is tightly stretched over and covers the at least one hole at the front surface of the panel. An electroacoustic sound source is configured to radiate acoustic waves against the back surface of the panel. The radiated acoustic waves travel through the at least one membrane-covered hole to vibrate at least one portion of the membrane which tightly covers the at least one hole. The at least one vibrating portion of the membrane radiates acoustic waves into the passenger compartment of the vehicle.

Claims

1. A low-profile panel assembly configured to provide sound having at least one acoustic wavelength within a passenger compartment of a vehicle having a support structure, the assembly comprising: a substrate panel perforated with at least one sub-wavelength hole which extends between front and back surfaces of the panel, the panel being configured to be attached to the support structure; a continuous membrane of facing material overlying and in contact with the panel, the membrane being tightly stretched over and covering the at least one hole at the front surface of the panel; and an electroacoustic sound source configured to radiate acoustic waves against the back surface of the panel, wherein the radiated acoustic waves travel through the at least one membrane-covered hole to vibrate at least one portion of the membrane which tightly covers the at least one hole and wherein the at least one vibrating portion of the membrane radiates acoustic waves into the passenger compartment of the vehicle.

2. The assembly as claimed in claim 1, wherein the substrate panel is a plastic molded panel.

3. The assembly as claimed in claim 2, wherein the plastic molded panel is injection molded.

4. The assembly as claimed in claim 1, wherein the substrate panel comprises an automotive vehicle trim panel.

5. The assembly as claimed in claim 1, wherein the substrate panel is concavely formed and the back surface of the substrate panel defines a recess in which the sound source is disposed.

6. The assembly as claimed in claim 5, wherein the sound source comprises a loudspeaker.

7. The assembly as claimed in claim 1, wherein the substrate panel is configured to be attached to a pillar of the support structure.

8. The assembly as claimed in claim 1, wherein the at least one hole is a microperforation which is laser-drilled in the substrate panel.

9. The assembly as claimed in claim 1, wherein the substrate panel is microperforated with a plurality of sub-wavelength holes.

10. The assembly as claimed in claim 1, wherein the facing material includes leather.

11. A low-profile panel assembly configured to provide sound having at least one acoustic wavelength within a passenger compartment of a vehicle having a support structure, the assembly comprising: a substrate panel perforated with an array of sub-wavelength holes which extend between front and back surfaces of the panel, the panel being configured to be attached to the support structure; a continuous membrane of facing material overlying and in contact with the panel, the membrane being tightly stretched over and covering the array of holes at the front surface of the panel; and a plurality of electroacoustic sound sources configured to radiate acoustic waves against the back surface of the panel wherein the radiated acoustic waves travel through the array of membrane-covered holes to vibrate portions of the membrane which tightly cover the array of holes and wherein the vibrating portions of the membrane radiate acoustic waves into the passenger compartment of the vehicle.

12. The assembly as claimed in claim 11, wherein the substrate panel is a plastic molded panel.

13. The assembly as claimed in claim 12, wherein the plastic molded panel is injection molded.

14. The assembly as claimed in claim 11, wherein the substrate panel comprises an automotive vehicle trim panel.

15. The assembly as claimed in claim 11, wherein the substrate panel is concavely-formed and the back surface of the substrate panel defines a recess in which the sound sources are disposed.

16. The assembly as claimed in claim 15, wherein the sound sources comprise loudspeakers.

17. The assembly as claimed in claim 11, wherein the substrate panel is configured to be attached to a pillar of the support structure.

18. The assembly as claimed in claim 11, wherein the array of holes are microperforations which are laser-drilled in the substrate panel.

19. The assembly as claimed in claim 11, wherein the substrate panel is microperforated with the array of sub-wavelength holes.

20. The assembly as claimed in claim 11, wherein the facing material includes leather.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] FIG. 1A is an interior, perspective, environmental view, partially broken away, of an automotive vehicle in which at least one embodiment of the present invention is radiating three sets of acoustic waves into a passenger compartment of the vehicle;

[0079] FIG. 1B is an enlarged view of a portion of the view of FIG. 1A contained within the dashed box of FIG. 1A to illustrate the relative size of a hole (illustrated in phantom) in a substrate panel of the assembly;

[0080] FIG. 2 is a view, partially broken away and in cross section, taken along lines 2-2 of FIG. 1A to illustrate loudspeakers, holes extending through the substrate panel and a continuous membrane covering the holes; and

[0081] FIG. 3 is a view, partially broken away and in cross-section, and partially in schematic, which illustrates an injection molding machine, a hole-drilling laser and an embodiment of an assembly constructed in accordance with the present invention.

DETAILED DESCRIPTION

[0082] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0083] As used herein, the term “microperforations” may include circular and/or non-circular shaped micro-holes. The term “non-circular” may include any arbitrary shape that is not circular. The term “diameter” may be taken to mean the minimum distance across an opening of the microperforation at a point through the centroid of the microperforation, where the centroid and diameter are based on the area of the microperforation on a surface of the panel in which the microperforation is present. For example, when the microperforations are substantially circularly cylindrical, the diameter is the distance across the center of the circle defining the opening.

[0084] The openings of the microperforations may be non-circular such that the microperforation is not circularly cylindrical. In these cases, the “diameter” may be taken to mean the minimum distance across the non-circular opening of the microperforation that crosses through the centroid. The terms “hole” and “microperforation” are used interchangeably.

[0085] In some embodiments, the microperforations have a generally circular cross-section through the thickness of the panel. In some embodiments, the microperforations have a non-circular cross-section through the thickness of the panel. In some embodiments, the shape of the microperforation through a cross-section of a panel varies, or is substantially constant.

[0086] In some embodiments, the diameter is between 0.02 mm and 5 mm, between about 0.05 mm and 2 mm, between about 0.1 mm and 2 mm, between about 0.1 mm and about 1 mm, between about 0.1 mm and 0.6 mm.

[0087] As used in this application, the term “substrate” refers to any flexible, semi-flexible or rigid single or multi-layer component having a surface to which a decorative membrane is or can be applied. The substrate may be made of polymers and other plastics, as well as composite materials. Furthermore, the shape of the substrate and particularly the surface to be covered can be any part of an assembly or device manufactured by any of various methods, such as, without limitation, conventional molding, extruding, or otherwise fabricated.

[0088] The term “overlies” and cognate terms such as “overlying” and the like, when referring to the relationship of one or a first, superjacent layer relative to another or a second, subjacent layer, means that the first layer partially or completely lies over the second layer. The first, superjacent layer overlying the second, subjacent layer may or may not be in contact with the subjacent layer; one or more additional layers may be positioned between respective first and second, or superjacent and subjacent layers.

[0089] Referring now to the drawing figures, a low-profile panel assembly, generally indicated at 10, is configured to provide sound (in the form of sets of acoustic waves 12) having at least one acoustic wavelength within a passenger compartment 14 of a vehicle, generally indicated at 16, having a support structure (not shown). The assembly 10 includes a substrate panel, generally indicated at 18, perforated with an array of sub-wavelength holes 20 which extends between front and back surfaces, 22 and 24, respectively, of the panel 18. The panel 18 is configured to be attached to the support structure.

[0090] The assembly 10 also includes a continuous membrane, generally indicated at 26, of facing material overlying and in contact with the panel 18. The membrane 26 is tightly stretched over the array of holes 20 at the front surface 22 of the panel 18.

[0091] A plurality of electroacoustic sound sources 28 are configured to radiate sets of acoustic waves 30 against the back surface 24 of the panel 18. The waves 30 travel through the array of membrane-covered holes 20 to vibrate portions 32 of the membrane 26 which tightly cover the array of holes 20. The vibrating portions 32 of the membrane 26 radiate the sets of acoustic waves 12 into the passenger compartment 14 of the vehicle 16.

[0092] The panel 18 may be made of a thermoplastic material. For example, the panel 18 may be made of a material such as a polycarbonate resin containing acrylonitrile, butadiene, and styrene (PC-ABS) material, thermoplastic elastomer etherether (TEEE), polypropylene, the product having the trade name Santoprene™ supplied by Monsanto Company, or a thermoplastic polyolefinic (TPO) material.

[0093] The substrate panel 18 may be a plastic molded panel.

[0094] The plastic molded panel 18 may be injection molded as illustrated by the injection molding apparatus 36 in FIG. 3.

[0095] The substrate panel 18 comprise an inner trim panel such as the A-pillar panel of FIG. 1A. However, it is to be understood that the panel assembly 18 may be for other pillars or panels within the passenger compartment 14.

[0096] The substrate panel 18 may be concavely formed and the back surface 24 of the substrate panel 18 may define a recess 40 in which the sound sources 28 are disposed.

[0097] The sound sources 28 may comprise loudspeakers.

[0098] The substrate panel 18 may be configured to be attached to a pillar (not shown) of the support structure.

[0099] The array of holes 20 may be microperforations drilled by a laser 42 of FIG. 3 into the substrate panel 18.

[0100] The substrate panel 18 may be microperforated with the array of sub-wavelength holes 20.

[0101] The facing material may be leather.

[0102] At least one embodiment of the present invention takes advantage of the scientific fact that the transmission of sound amplitude in air through walls perforated with subwavelength holes produces intensity enhancements therein. This acoustic transmission is achieved with thin tensioned circular membranes, making the mass of the air in the holes effectively vanish. Imaging the pressure field confirms incident-angle independent transmission, thus realizing a bona fide invisible wall.

[0103] This scientific fact is described in the paper entitled, “Giant Acoustic Concentration by Extraordinary Transmission in Zero-Mass Metamaterials,” Phys. Rev. Lett. 110, 244302 (2013).

[0104] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.