Methods for forming a hidden audio assembly

Methods and systems are provided for a vehicle headliner. In one example, a method for forming the headliner includes forming a recess and an opening for a support structure in a base substrate layer of the headliner during heat treatment of the base substrate layer. The method further includes inserting the support structure in the recess and the opening and covering the base substrate layer with a skin. A positioning of the support structure within the base substrate layer allows an outline of the support structure to be undetectable through the skin by sight or touch.

FIELD

The disclosure relates to a hidden audio assembly for a vehicle.

BACKGROUND

Modern vehicles may be configured with noise management systems to control a character of audible noise in a vehicle cabin. For example, it may be desirable to reduce intrusiveness of road noise, powertrain noise, vehicle noise, vibration, and harshness (NVH), etc. into the cabin. Furthermore, systems relying on audio frequency transmission and detection within the cabin, such as a hands-free telephony capability and identification of spoken commands via voice recognition, may be implemented in the vehicle.

Such systems may rely on a network of audio equipment, including microphones and speakers, installed in various locations in the vehicle cabin. For example, microphones may be located in a headliner of the vehicle, positioned in regions proximate to vehicle passengers to enable maximum reception of audio frequencies. The microphones may be embedded in the headliner and maintained in place by support structures, such as bezels and grills. The support structure may be visible, thereby disrupting a clean, uninterrupted visual aesthetic of the headliner.

SUMMARY

Embodiments are disclosed for a microphone assembly support structure. The support structure may be configured to be embedded in a region of a vehicle, such as a vehicle headliner, such that the microphone assembly is invisible from an exterior surface of the headliner. In one embodiment, a method for forming a headliner includes forming a recess and an opening for a support structure in a base substrate layer of the headliner during heat treatment of the base substrate layer. The support structure if inserted into the recess and the opening covered with a skin. A positioning of the support structure within the base substrate layer allows an outline of the support structure to be undetectable through the skin by sight or touch.

In another embodiment, a method for manufacturing a headliner for a vehicle includes forming an opening in a base substrate layer of the headliner by pressing a wall of a bracket into the base substrate layer until a top plate of the bracket is flush with a first surface of the base substrate layer. A portion of the base substrate layer enclosed by the wall of the bracket is removed and the base substrate layer is covered along the first surface with a skin.

In yet another embodiment, a method for forming a layered assembly with a hidden support structure includes embedding the support structure in a base substrate layer of the layered assembly and covering the support structure with a skin. The support structure is perforated to allow passage of acoustic signals covering the support structure with the skin allows the support structure to be invisible.

DETAILED DESCRIPTION

Modern vehicles may include a variety of sound management systems and devices that cooperate to manage an aural environment within a vehicle. For example, a vehicle may include a road noise cancellation (RNC) system that is configured to reduce the amount of road noise heard by vehicle occupants. Such systems may operate by receiving input from one or more microphones and/or sensors and outputting a signal to one or more loudspeakers that modifies the sound pattern. The systems can mask unwanted road and engine noise making the cabin seem quieter. Other applications may include hands-free communication systems and telephone applications. Other vehicle sound management systems may include active noise control (ANC) and in-car communication (ICC) systems.

These vehicle systems use one or more microphones to receive sound/noise input. The microphones may be installed at various locations within the vehicle. Sound propagates through air as a pressure wave. A source may generate a sound by causing a vibration in the air (or other medium). These vibrations then propagate from the source through the medium (e.g., air). A microphone may operate by receiving these pressure waves and converting the pressure waves into an electrical signal. To accomplish this, the microphone element may need to be exposed to the pressure wave.

Existing in-vehicle microphones receive the pressure wave through openings that expose the cabin air to the microphone elements. As an example, a microphone and/or sensor, e.g., a microphone assembly, may be installed in a headliner of the vehicle. The microphone assembly for installation in the headliner may include a visible A-surface grill that defines one or more openings. The A-surface may be that surface that is visible within the vehicle cabin. The microphone assembly may include a housing that attaches to the grill from a B-side of the headliner. The B-side may be that surface opposite the A-surface and is generally not visible within the cabin. These grills are generally visible within the cabin and may be aesthetically displeasing. In addition, the openings can allow dust and moisture intrusion into the microphone element which may cause reduced performance.

The increase in the number of headliner microphone grills has led to a demand for a microphone assembly that does not rely on an A-surface grill, i.e. an “invisible” microphone assembly. One challenge of integrating a microphone assembly into the headliner is the alignment of holes in the headliner to holes in the microphone assembly. Furthermore, it may be necessary to locate the microphone further away from the headliner which may lead to sealing problems and nonlinear microphone frequency response.

Embodiments disclosed herein include an invisible microphone assembly and insert support structure embedded into the headliner of a vehicle. A cut-out location for the microphone assembly is provided that may have a sufficiently large diameter to accommodate the microphone assembly. Embodiments include the insert support structure, which may be a bracket or a plate, integrated between the substrate and A-surface layers of the headliner, as described further below. It will be appreciated that while the assembly is described below with respect to a microphone assembly, the hidden configuration of the assembly may be applicable to a variety of audio devices, such as speakers.

FIG.1depicts a block diagram of a vehicle100that includes a control module102. The control module102may include a microprocessor and memory to implement various features and functions. For example, the control module102may be part of an RNC system or an ANC system. The control module102may be part of an ICC system that manages in-vehicle communications. The control module102may also be configured as a sound processor to implement telematics features such as speech recognition and hands-free system operation.

The control module102may be electrically connected to one or more microphones104. The microphones104may be in different positions within the vehicle100. The microphones104may be configured to generate an electrical signal representing sound or noise at the position of the microphones104. The control module102may be electrically connected to one or more speakers106, e.g., loudspeakers106. The loudspeakers106may be configured to generate sound based on signals received from the control module102. The vehicle100may further include a user interface108. In some examples, the user interface108may be a touch-screen display that can display content from the control module102and provide inputs (e.g., menu selections) to the control module102. The user interface108may also include buttons and switches. The configuration and usage of the user interface108may depend on the purpose of the control module102. The vehicle100may further include a headliner (not shown inFIG.1). The headliner may be configured to line an interior of a roof of the vehicle100. The headliner may be configured to provide noise and thermal insulation within the cabin of the vehicle. The headliner may also be configured for mounting various components. For example, lights, control panels, and microphones may be mounted to the headliner.

Embedding a concealed microphone in a headliner may face structural challenges. The space available for a microphone setup is often constrained due to arrangement of other components coupled to the headliner, and the setup may impede audio detection by the microphone. Ease of installation is also a concern given these constraints. The support assembly shown inFIGS.2A-2Brepresents a setup that has relatively low space requirements with a straightforward installation, while also maintaining effective audio detection.

FIG.2Adepicts an exploded view of first example of a headliner assembly200that is configured to be installed in a vehicle headliner andFIG.2Bshows a cross-section of the headliner assembly200, taken along line A-A′ shown inFIG.2A. A set of reference axes201are provided for comparison between views shown, indicating a y-axis, an x-axis and a z-axis. The headliner assembly200includes a microphone support assembly202embedded in layers of the headliner. While the example is directed toward installation in the vehicle headliner, the concepts and assemblies may also be applied to other areas of the cabin (e.g., side trim, dashboard, console). The vehicle headliner may be a multi-layer construction, e.g., a layered assembly, including a base substrate layer204that provides a backing and structural integrity of the headliner. The base substrate layer204may be constructed of a composite material having application-specific stiffness, strength, and insulating characteristics. For example, the base substrate layer204may be a relatively rigid, e.g., inflexible, foam and may also be referred to as a hard or core foam layer.

The base substrate layer204is covered by a middle foam layer206, which is covered by a covering208which may form an A-side of the headliner assembly200. A bottom surface203of the base substrate layer204may therefore be a B-side of the headliner assembly200. Together, the middle foam layer206and the covering208form a skin of the headliner assembly200. The middle foam layer206may be a soft, flexible foam and the covering208may be a material that allows acoustic waves, e.g., pressure waves, to penetrate through the material. For example, the covering208may be an acoustic fabric configured to be acoustically translucent. Each of the middle foam layer206and the covering208may be thinner than the base substrate layer204, where a thickness of each layer is defined along the y-axis, and furthermore, a combined thickness of the middle foam layer206and the covering208may be less than a thickness of the base substrate layer204. However, in other examples, the thickness of the base substrate layer204may be similar to or thinner than the skin.

The middle foam layer206may be bonded or otherwise secured to the covering208to form the skin of the headliner. The covering208may be similarly bonded or otherwise secured to the middle foam layer206. For example, the covering208and the middle foam layer206may be bonded by flame lamination and applied to the base substrate layer204as a single layer. In some configurations, the skin may be stretch fit across the base substrate layer204. It will be appreciated that the layers of the headliner may be coupled to one another by different techniques without departing from the scope of the present disclosure.

The headliner may be oriented in a vehicle cabin such that the covering208is proximate to the vehicle cabin, e.g., an upper face of the covering208, with respect to the y-axis, faces the vehicle cabin, while the base substrate layer204is distal to the vehicle cabin. As such, the covering208may be configured to provide a desired aesthetic and/or texture to the headliner.

As described above, the microphone support assembly202may be embedded in the headliner layers. In one example, as shown inFIGS.2A and2B, the microphone support assembly202may include a bracket300which may be integrated into, e.g., circumferentially surrounded and recessed into the base substrate layer204to anchor a microphone housing214, as shown inFIG.2B. The bracket300may have an upper face306, with respect to the y-axis, that is arranged flush with an upper surface218of the base substrate layer204when the bracket300is inserted into an opening or void210formed in the base substrate layer204.

Dimensions, e.g., a width, height, and depth of the void210may be configured to receive the bracket300without any space between inner surfaces of the void210and outer surfaces of the bracket300. As such, the base substrate layer204may have a sealing engagement with the bracket300. The upper surface218of the base substrate layer204may also be adapted with a recess212with similar dimensions as the top surface of the bracket300to enable recessing of the top surface of the bracket300into the base substrate layer204to allow the upper face306of the bracket300to be continuous and co-planar, with the upper surface218of the base substrate layer204, as shown inFIG.2B. When inserted into the void210, the bracket300is in face-sharing contact with a surface205of the recess212. Further details of the bracket300are provided below with reference toFIGS.3A-3C.

An example of a positioning of a bracket within a base substrate layer, as described above, is shown inFIG.4. Therein, a bracket400, which may be an alternate embodiment of the bracket300ofFIGS.2A-3C, has atop plate402recessed into a base substrate layer404of a headliner. The top plate402is flush with an upper surface, e.g., a surface of the base substrate layer404configured to be in face-sharing contact with a skin406of the headliner. Thus, when the skin406is covering the top plate402, an outline of the top plate402is invisible.

Returning toFIGS.2A and2B, the microphone support assembly202may also include the microphone housing214. The microphone housing214may be configured to enclose and provide structural support for a microphone/sensor (not shown). The microphone housing214may be formed of a plastic material, but is not limited as such. In one example, the microphone housing214may have a snap-fit engagement with the wall304of the bracket300to secure the microphone housing214to the bracket300. Additionally, in some examples, foam tape may be used to form an acoustic seal between the microphone housing214and the bracket300.

The microphone/sensor enclosed within the microphone housing214may include a connector that is configured to receive an electrical connector to transfer electrical signals from the microphone to another system (e.g., the control module102ofFIG.1). As an example, the microphone may utilize microelectromechanical systems (MEMS) technology and may be an integrated circuit/sensor assembly. The microphone may be configured to convert an acoustic wave at the sensor assembly into an electrical signal. For example, the microphone may detect audio signals within the vehicle cabin and relay the signal, as the electrical signal, to the control module for further processing.

Thus when assembled, the headliner assembly200may be formed of a bonded stack of the base substrate layer204, the skin (e.g., the middle foam layer206and the covering208) and the microphone support assembly202embedded therein. The bracket300may be inserted into the headliner assembly200such that the bracket300is arranged only in the base substrate layer204, e.g., the bracket300does not protrude into the middle foam layer206of the skin. The skin may thereby have a smooth, uninterrupted appearance across a region where the microphone support assembly202is located.

For example, as shown inFIG.5, a microphone support assembly may be installed in a flat, e.g., planar, region502of a headliner500. InFIG.5, the region502is positioned proximate to an opening504for a sunroof opening and spaced away from a region506where a sun visor may be located. Both the outline of the bracket and the location of the microphone/sensor are visually undetectable. The appearance of the microphone support assembly is concealed such that an occupant of the vehicle cabin may not be able to detect the presence of the microphone support assembly during inspection. In addition, the microphone is separated from the vehicle cabin only by a thickness of the skin and a thickness of a top plate of the insert support structure, thus minimizing impingement of audio signals by layers of the headliner.

The bracket300ofFIGS.2A-2Bis shown inFIGS.3A,3B, and3Cfrom a top view, a bottom view and a side view, respectively, and will be discussed collectively. The bracket300may be a rectangular structure, e.g., rectangular along the x-z plane, of rigid material such as plastic or metal. The bracket300has a top plate302and a continuous wall304which may, in one example, be continuous with one another, forming a single, unitary structure. As another example, the top plate302and the wall304may be formed separately and attached to one another by a method such as welding. The top plate302and the wall304may be formed of a same or different material.

The top plate302may be a flat, solid plate with a rectangular outer geometry and the upper face306opposing a lower face308. The upper face306of the top plate302may be in face-sharing contact with a surface of a middle foam layer of a skin, e.g., the middle foam layer206ofFIG.2. The wall304may be attached to the lower face308of the top plate302, protruding perpendicularly away from the top plate302along the y-axis, as shown inFIG.3C.

The wall304may be continuous, e.g., without breaks, and may form a rectangular shape when viewed along the y-axis, as shown inFIG.3B. A central cavity310of the bracket300may be formed and enclosed by the wall304and may be configured to house a microphone, as described above.

A length312, as defined along the z-axis, and a width314, as defined along the x-axis, of the central cavity310may each be smaller than a length316and a width318of the top plate302, as shown inFIG.3B. As such, the top plate302has an outer extension320that continuously frames the wall304when viewed along the y-axis. The outer extension320may be an overhang of the top plate302that extends along the x-z plane beyond the length312and the width314of the central cavity310, along all sides of the top plate302. In one example, the outer extension320may be sufficiently large to allow the outer extension320to be adhered to the base substrate layer without becoming visible through the skin. As an example, the outer extension320may extend a distance of 1 cm around the wall304. However, in other examples, a size of the outer extension320may be reduced if an additional bracket or attachment, such as a ring attached to a surface of the wall304were positioned at the B-side of the base substrate layer to brace the bracket300and maintain the bracket300in place. The lower face308of the top plate302may be in face-sharing contact along the outer extension320with a surface of the base substrate layer at the recess when the bracket300is embedded in the base substrate layer. A region of the lower face308enclosed by the wall304may be in contact with the microphone/sensor.

A bottom edge322of the wall304and of the bracket300may be flat and parallel with the top plate302along the x-z plane, as shown inFIG.3C. A height324of the wall304may be greater than a height326of the top plate302. However, in other examples, the height324of the wall304may vary relative to the height326of the top plate302. For example, the height324of the wall304may be increased or decreased based on a thickness of a base substrate layer, e.g., the base substrate layer204ofFIG.2, of the headliner while the height326of the top plate302may depend on a material used to form the top plate302. The recessing of the top plate302into the base substrate layer204, however, may constrain the height of the top plate302to be less than the thickness of the base substrate layer204. In other examples, the height of the top plate302may be not constrained if a shape of the base substrate layer204is molded to accommodate the top plate302by forming a recessed pocket.

A thickness330of the wall304, as shown inFIG.3B, may vary depending on a material strength of the bracket300and a process of forming the void in the base substrate layer (e.g., whether the void is formed prior to inserting the bracket300or vice versa). For example, the thickness330of the wall304may be 0.5 mm if formed from metal or 2 mm if formed from plastic. The thickness330may be optimized to allow the wall304to slice easily into the base substrate layer when the base substrate layer is heated and softened while providing sufficient structural support to the microphone coupled thereto. In other words, the thickness330of the wall304may be a balance between a cutting ability and stabilizing capability. In one example, the thickness330of the wall304may be uniform throughout the wall. In another example, the thickness330of the wall304may taper to become thinner at the bottom edge322, similar to a cookie cutter, to allow the bottom edge322to cut into the base substrate layer with minimal resistance while maintaining a robustness of the wall304.

Furthermore, while the bracket300is depicted with an overall rectangular geometry, it will be appreciated that the bracket shown herein is a non-limiting example. The overall shape and dimensions of the bracket300and the central cavity310may be varied to facilitate installation of the bracket with differently shaped and sized microphone assemblies. For example, the bracket may have an outer geometry that is elliptical, square, quadrilateral, etc. As another example, a size of the central cavity310, relative to the top plate302, may vary, thus modifying a size of the outer extension320of the top plate302. The configuration may also be installed in other areas of the vehicle cabin, as described above.

The top plate302may also include one or more openings328extending entirely through the height326, e.g., a thickness, of the top plate302. In other words, the openings328may be through-holes. The openings328may be aligned with the central cavity310of the bracket300, e.g., along the y-axis, and therefore aligned with a microphone assembly (e.g., a microphone, a sensor, etc.) housed in the central cavity310. The openings328may be formed in the top plate302of the bracket300before or after insertion of the bracket300into the base substrate layer.

In one example, as shown inFIGS.3A and3B, the openings328may be three circular holes centered within the top plate302and aligned along the z-axis. In one example, a diameter of each of the openings328may be between 1-4 mm. The openings328may allow unimpeded passage of sound through the top plate302while maximizing an unperforated portion of the top plate302. In this way, the top plate302may have sufficient surface area to provide structural support to the skin to circumvent sagging of the skin across the top plate302of the bracket300. As such, the bracket300allows the headliner assembly200to be configured in a hidden arrangement, where both an outline of the bracket300and the microphone are invisible. While three circular openings are depicted inFIGS.3A and3B, various shapes, quantities, arrangements, and sizes of the openings328are possible.

In some examples, the openings328may be extended through the skin. As shown inFIG.6, an opening600, which may be an embodiment of one of the openings328ofFIGS.3A-3B, may be formed through both a top plate602of a bracket, e.g., the bracket300ofFIGS.2-3C, and a skin604in face-sharing contact with the top plate602. The opening600may be surrounded by a rivet606to maintain an alignment of the opening600through the top plate602and the skin604. The rivet606may protrude from surfaces of both the skin604and the top plate602. A protruding portion of the rivet606from a surface of the skin604facing into a vehicle cabin may be visible. As such, the rivet606may be positioned in a region of the skin604configured with a graphic or a texture to camouflage the rivet606. As another example, a visibility of the rivet606may be obscured by positioning the rivet606behind a structure in the headliner, e.g., adjacent to a light. In some examples, a diameter of the opening600, and hence a diameter of the rivet606, may be sufficiently small to be difficult to detect visually.

In some examples, the bracket may also be used for a semi-hidden arrangement of an audio device, such as a microphone assembly. More specifically, in instances where the skin is formed of a thicker, more durable material, additional treatment of the skin may be demanded. For example, the thicker skin may not allow unimpeded passage of acoustic signals therethrough and may be perforated to offset an adverse effect on sound transmission to the microphone assembly enclosed within the headliner assembly. As a result, the microphone assembly may be invisible but an outline of the microphone assembly may be indicated by visible perforations along the skin of the headliner. In some examples, the visible perforations may be configured with rivets, such as the rivet606shown inFIG.6.

In such instances, as well as when a thinner, acoustically translucent skin is applied to the base substrate layer, the headliner assembly may include a microphone support assembly with only a top plate, e.g., similar to the top plate302of the bracket300ofFIG.3, and without a wall (e.g., the wall304). A second example of a headliner assembly1000for a semi-hidden configuration of a microphone support assembly1002is shown in an exploded view inFIG.10Aand in a cross-sectional view inFIG.10B, the cross-section taken along line B-B′ ofFIG.10A. The headliner assembly1000includes the base substrate layer204, void210, recess212, microphone housing214ofFIG.2which will not be re-introduced. The microphone support assembly1002includes a top plate1010, in addition to the microphone housing214.

The top plate1010may be formed of a thin metal or plastic sheet configured to be nested in the recess212of the base substrate layer204and may have dimensions (e.g., a thickness, width, and length), similar to dimensions of the recess212. As shown inFIG.2B, when the headliner assembly1000is assembled, an upper face1008of the top plate1010may be flush with the upper surface218of the base substrate layer204. A recessing of the top plate1010into the base substrate layer204positions the top plate1010such that the top plate1010does not protrude into a skin1012of the headliner assembly1000.

The skin1012, in one example may be the skin shown inFIGS.2A-2B, including a middle foam layer bonded to a covering (e.g., the middle foam layer206and the covering208ofFIGS.2A-2B). As another example, the skin may be a layer of a thicker material, such as leather, where the thicker material may or may not be bonded to the middle foam layer. When the skin1012is formed of the thicker material, acoustic signals may not readily penetrate through the skin1012, as described above. In such instances, the skin1012and the top plate1010may be perforated together to form perforations1014, or through-holes1014that extend entirely through the skin1012and the top plate1010. The through-holes1014may be sufficiently small in diameter to maintain the structural support provided by the top plate1010. In addition, in some examples, a graphic, such as a logo, may be added to the skin1012across the top plate1010to provide a desired aesthetic or accessory structures, such as the rivet606ofFIG.6may be applied to at least some of the through-holes1014.

The through-holes1014in the top plate1010may form a grille for the microphone/sensor enclosed in the microphone housing214. A configuration of the through-holes1014, e.g., a layout and a quantity, may therefore vary from the configuration shown inFIGS.10A-10Bdepending on the microphone/sensor. Furthermore, when the skin1012is formed from the thinner covering bonded to the middle foam layer to foam an acoustically translucent skin, the perforations1014may extend only through the top plate1010and not the skin1012.

In some examples, the microphone support assembly1002may also include an optional B-side bracket1004. Whereas the bracket300ofFIGS.2A-3may be an A-side bracket with the top plate closer to the A-side of the headliner assembly than the B-side, the B-side bracket1004ofFIGS.10A-10Bmay have a bottom plate1003that abuts the bottom surface203of the base substrate layer204. A continuous wall1005is coupled to the bottom plate1003and extends upwards and perpendicularly from the bottom plate1003. Furthermore, the B-side bracket1004has a central opening1006that extends through the bottom plate1003, as shown inFIG.10B. As described above, use of a rectangular bracket is for illustrative purposes only and other geometries are possible.

A height of the bracket1004, as defined along the y-axis, may be similar to a distance between the bottom surface203of the base substrate layer and the surface205of the recess212. When the headliner assembly1000is fully assembled, the wall1005of the bracket1004may be entirely enclosed within the void210and the bracket1004may be hot-glued to maintain a position of the bracket1004within the base substrate layer204. The top plate1010may provide structural support to the skin1012across an area occupied by the microphone support assembly1002which may otherwise cause sagging and loss of tautness across the central opening1006of the bracket1004.

Acoustic signal transmission through the semi-hidden or hidden headliner assembly1000may be enabled by the through-holes1014. When only the top plate1010is used, the void210may be cut in the base substrate layer204such that the void210is aligned with the recess212. The microphone housing214is inserted through the void210and may be directly adhered to the top plate1010. Additionally or alternatively, the microphone housing214may be inserted into the central opening1006of the bracket1004and attached to the bracket1004by fasteners, clips, etc., when the bracket1004is included.

An example of a semi-hidden arrangement of a microphone is depicted inFIG.7. Therein, an interior panel700of a vehicle door is shown. The interior panel700includes an outer layer of leather covering a metal sheet, both of which are perforated in a uniform manner. A microphone support assembly is hidden by the outer layer of leather and the metal sheet. It will be appreciated that a similar configuration may be used in a vehicle headliner.

One or more insert support structures, such as the bracket300ofFIGS.2A-3Cor the top plate1010ofFIGS.10A-10B, may be inserted into a base substrate layer of a headliner during a heat treatment of the base substrate layer. For example, as shown in a schematic inFIG.8, a hot form press800may be used to heat and mold the headliner into a suitable shape for installation in a vehicle cabin. The hot form press800may have an upper press802and lower press804with heating elements to heat a base substrate layer806. The upper press802and the lower press804may also include matching halves of a mold. Upon heating, the base substrate layer806may soften and conform to a shape of the mold when the upper press802is lowered to come into contact with the base substrate layer806, as indicated by arrows808.

The softening of the base substrate layer806may also allow one or more of the bracket300to be pressed into the base substrate layer806, as indicated by arrows810. The wall of the bracket300, e.g., the wall304ofFIGS.2and3B-3C, may be of a suitable thickness to cut through the base substrate layer806readily without causing deformation of the bracket300. The bracket300may be inserted into the base substrate layer806by placing the bottom edge of the bracket300(e.g., the bottom edge322ofFIGS.3B-3C) against an upper surface of the base substrate layer806and applying force until the upper face (e.g., upper face306) of the bracket300is flush with the upper surface of the base substrate layer806. Alternatively, if a top plate, such as the top plate1010ofFIGS.10A-10Bis used instead of the bracket300, the top plate is pressed into the base substrate layer806until the upper face (e.g., the upper face1008) of the top plate is flush with the upper surface of the base substrate layer806. A portion of the base substrate layer may be removed from the central cavity/opening of the bracket, thereby providing a space for housing a microphone assembly (e.g., a microphone, a sensor, connectors, etc.). The microphone assembly may be coupled to the bracket through the B-side of the headliner.

The bracket may be inserted into the heated base substrate layer while the base substrate layer is molded to a desired shape. Insertion of the bracket may be performed by adapting the hot form press800with retaining structures, such as clips or fingers at the upper press802. The lower press804may have recesses to assist in material displacement in at the base substrate layer806caused by insertion of the bracket.

An example of a method900for forming a headliner assembly with one or more audio assemblies is shown inFIG.9. The headliner assembly may, in one example, be the headliner assembly200ofFIGS.2A-2B, including a base substrate layer coupled to a skin, the skin formed of a middle foam layer and a covering. The base substrate layer may be formed of a more rigid material than the skin. An insert support structure, such as the bracket300ofFIGS.2A-3Cor the top plate1010ofFIGS.10A-10B, may be inserted and embedded into the headliner assembly during method900to enable subsequent coupling of a microphone assembly to a central cavity or central opening of the bracket or void in the base substrate layer. Method900may be implemented at a headliner manufacturing plant or system, including a series of instrument and machines configured to perform various processing steps during formation of the headliner assembly. Operation of the instruments and machines may be controlled by a system controller, e.g., when the method is configured as an automated method, or by one or more operators.

At902, the method includes cutting the base substrate layer to desired dimensions. For example, the base substrate layer may be initially formed as a sheet and may be trimmed to dimensions similar to a ceiling of a vehicle cabin. The method includes processing the base substrate layer via a heat treatment at904. Heat treating the base substrate layer includes, at906, heating the cut base substrate layer in a hot form press, such as the hot form press800ofFIG.8. For example, the base substrate layer may be placed on a lower press of the hot form press and heated to a target temperature. Heating the base substrate layer to the target temperature may cause the rigid material of the base substrate layer to soften and become malleable.

The heat treatment of the base substrate layer further includes, at908, forming an opening or void in the base substrate layer for inserting the bracket. Forming the void may, in one example, include pressing a bottom edge of a wall of the bracket into a first face of the base substrate layer such that the wall of the bracket cuts into the base substrate layer from the first face through an entire thickness of the base substrate layer to a second, opposite face. For example, the bottom edge of the wall may become flush with the second face of the base substrate layer. As such, a height of the bracket may be configured to be similar to or less than the thickness of the base substrate layer.

Upon pressing the bracket into the base substrate layer to allow the wall to cut into the base substrate layer, a portion of the base substrate layer enclosed within the wall may be removed mechanically or by vacuum through a space in a lower press of the hot form press.

Alternatively, when the top plate is used, the void may be cut into the base of substrate layer at the hot form press using a cutting tool. The cut portion of the base substrate layer may be similarly removed either mechanically or by vacuum. In some examples, a B-side bracket, such as the B-side bracket1004ofFIGS.10A-10B, may be inserted into the void and adhered to the base substrate layer, e.g., by hot-glue.

The insert support structure may be pressed until a top plate of the bracket/the top plate is flush with the first face of the base substrate layer, e.g., an upper face of the top plate is co-planar and continuous with the first face of the base substrate layer, thus forming a recess in the base substrate layer at the first face in which the top plate is nested. A portion of the base substrate layer enclosed by the wall, e.g., the portion of the base substrate layer within a central cavity of the bracket when the bracket is the bracket300ofFIGS.2A-3C, is removed, thereby forming the void.

Heat treatment of the base substrate layer further includes molding the base substrate layer at912. The heated base substrate layer, with the embedded bracket, may be stamped at the hot form press to mold the base substrate layer to a desired geometry to match contours of the vehicle cabin ceiling.

It will be appreciated that while insertion of a single insert support structure is described above, one or more insert support structures may be inserted and embedded into the base substrate layer. The insert support structures may be arranged in target regions of the headliner, configured to maximize reception of audio frequencies. For example, the insert support structures may be positioned behind sun visors above a windshield of the vehicle or adjacent to passengers in rear seats of the vehicle.

In another example, the void in the base substrate layer may instead be formed by cutting the recess and the void prior to insertion of the insert support structure, e.g., pre-cut, during heat treatment of the base substrate layer once the base substrate layer is heated (e.g.,906). For example, the base substrate layer is molded and the opening for the insert support structure is cut (e.g.,912and908) first. The mold may then be opened and/or the base substrate layer transferred to another similar mold where the insert support structure is inserted (e.g.,910). A final molding of the base substrate layer may be performed which presses the insert support structure flush with the base substrate layer (e.g.,912is repeated).

At914, the method includes removing the molded base substrate layer from the hot form press and cooling the base substrate layer. In one example, the base substrate layer may be air-cooled. However, other cooling methods may be used. Upon cooling, the base substrate layer may regain sufficient rigidity to allow easier handling and manipulation. A position of the insert support structure may be maintained as a result of the hot pressing of the insert support structure against a surface of the recess (e.g., adherence between the outer extension320of the bracket300and the surface205of the recess as shown inFIGS.2A-2B) or by molding small fingers321along the outer extension of the bracket/face of the top plate. As another example, the insert support structure may be held in place by a pre-applied adhesive which may be activated by heat. Furthermore, as described above, the B-side bracket may be installed via a snap-fit engagement with the insert support structure. An adhesive may additionally be used to secure the position of the B-side bracket to circumvent shifting and/or sliding of the B-side bracket. Techniques for maintaining the position of the insert support structure may be applied before or after application of the skin.

The skin is added to the cooled base substrate layer at916as an uninterrupted, e.g., without holes, outer layer of the headliner assembly across the insert support structure. A profile of the skin across the top plate of the insert support structure may be smooth and without protrusions such that an outline of the top plate is not discernible by sight or touch. The covering and the middle foam layer may be coupled to one another prior to adhesion to the base substrate layer to form the skin. The skin may be coupled to the base substrate layer with the middle foam layer facing the base substrate layer. Once the skin is coupled to the base substrate layer, the skin and the top plate/the top plate of the bracket may be perforated together if the perforations are to be through-holes for a semi-hidden configuration of the headliner assembly. However, if the microphone assembly is to be hidden, the top plate/the top plate of the bracket may be already perforated prior to insertion in the base substrate layer.

At918, the headliner assembly, e.g., a laminated stack formed by the base substrate layer and the skin with the insert support structure embedded therein, may be trimmed to a final desired shape matching a geometry of the vehicle cabin ceiling. For example, excess skin may be trimmed to follow an outer edge of the base substrate layer. The method ends and the headliner assembly may be further processed at another facility or processing system to install a microphone in the central cavity of the insert support structure.

By utilizing an insert support structure embedded into a base substrate layer of a headliner assembly, a headliner assembly with one or more hidden audio assemblies is provided. The insert support structure may be entirely hidden by a skin of the headliner assembly such that the skin is free of protrusions and read-through lines, yielding an audio assembly that is undetectable by sight or touch. A demand for aligning a microphone and sensor of the audio assembly with holes in the headliner is precluded, allowing easier installation of array microphones and sensors. The insert support structure reduces an unsupported area of the skin extending across the audio assembly, thus maintaining a smooth, continuous aesthetic of the headliner. An adverse effect of the skin on acoustic signal transmission to the audio assembly is lessened. The use of the insert support structure enables efficient audio assembly installation and arrangement of the audio assembly in tight spaces and reduces rear noise rejection by minimizing noise leakage through a rear side (e.g., a B-side) of the headliner assembly. Furthermore, the audio assembly is located closer to an interior of the vehicle compared to conventional methods.

The description of embodiments has been presented for purposes of illustration and description. Suitable modifications and variations to the embodiments may be performed in light of the above description or may be acquired from practicing the methods. The described methods and associated actions may also be performed in various orders in addition to the order described in this application, in parallel, and/or simultaneously. The described systems are exemplary in nature, and may include additional elements and/or omit elements. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed.

The disclosure also provides support for a method for forming a headliner, comprising: forming a recess and an opening for a support structure in a base substrate layer of the headliner during heat treatment of the base substrate layer, inserting the support structure in the recess and the opening, and covering the base substrate layer with a skin, wherein a positioning of the support structure within the base substrate layer allows an outline of the support structure to be undetectable through the skin by sight or touch. In a first example of the method, forming the opening for the support structure includes pressing the support structure into the base substrate layer and allowing a wall of the support structure to cut through a thickness of the base substrate layer until a top plate of the support structure, the top plate arranged perpendicular to the wall, is flush with a surface of the base substrate layer configured to be coupled to the skin. In a second example of the method, optionally including the first example, forming the recess includes pressing a top plate of the support structure, the top plate arranged co-planar with the skin and the base substrate layer, into the base substrate layer until an upper face of the top plate is flush with a surface of the base substrate layer configured to be coupled to the skin. In a third example of the method, optionally including the first and second examples, forming the opening for the support structure further includes removing a portion of the base substrate layer between the top plate and a B-side of the headliner to form a space to accommodate insertion of an audio assembly. In a fourth example of the method, optionally including the first through third examples, covering the base substrate layer with the skin enables the audio assembly to be visually undetectable through the skin. In a fifth example of the method, optionally including the first through fourth examples, inserting the support structure in the recess and the opening includes separating the audio assembly from an interior of a vehicle cabin by a thickness of the skin and a thickness of the top plate. In a sixth example of the method, optionally including the first through fifth examples, inserting the support structure in the recess and the opening includes maintaining a position of the support structure in the base substrate layer based on a plurality of fingers molded into a face of a top plate of the support structure. In a seventh example of the method, optionally including the first through sixth examples, the method further comprises: perforating atop plate of the support structure to form through-holes in the top plate and wherein the through-holes are configured to be aligned with an audio assembly. In an eighth example of the method, optionally including the first through seventh examples, forming the through-holes includes inserting rivets into the through-holes, the rivets protruding outwards from at least one surface of the base substrate layer. In a ninth example of the method, optionally including the first through eighth examples, forming the recess and the opening includes cutting the opening into the base substrate layer prior to inserting the support structure to form the recess.

The disclosure also provides support for a method for manufacturing a headliner for a vehicle, comprising: forming an opening in a base substrate layer of the headliner by pressing a wall of a bracket into the base substrate layer until a top plate of the bracket is flush with a first surface of the base substrate layer, removing a portion of the base substrate layer enclosed by the wall of the bracket, and covering the base substrate layer along the first surface with a skin. In a first example of the method, forming the opening in the base substrate layer includes heating the base substrate layer until the base substrate layer becomes more malleable to allow the wall of the bracket to cut into the base substrate layer. In a second example of the method, optionally including the first example, removing the portion of the base substrate layer enclosed by the wall of the bracket includes forming a void within a central cavity of the bracket, the bracket configured to house and support a microphone within the central cavity. In a third example of the method, optionally including the first and second examples, configuring the bracket to house and support the microphone includes adapting the top plate of the bracket with one or more openings aligned with the microphone. In a fourth example of the method, optionally including the first through third examples, pressing the wall of the bracket into the base substrate layer includes pressing a bottom edge of the wall against the first surface of the base substrate layer until the bottom edge reaches a second surface of the base substrate layer, the second surface opposite of the first surface. In a fifth example of the method, optionally including the first through fourth examples, covering the base substrate layer with the skin includes adhering a middle foam layer of the skin to the first surface of the base substrate layer and wherein the middle foam layer is in face-sharing contact with both the first surface of the base substrate layer and the top plate of the bracket.

The disclosure also provides support for a method for forming a layered assembly with a hidden support structure, comprising: embedding the support structure in a base substrate layer of the layered assembly and covering the support structure with a skin, the support structure perforated to allow passage of acoustic signals, and wherein the support structure is invisible when covered by the skin. In a first example of the method, allowing passage of sound waves further includes perforating the support structure and the skin together to align a plurality of perforations in the support structure and the skin. In a second example of the method, optionally including the first example, aligning the plurality of perforations by perforating the support structure and the skin together includes performing the perforating after embedding the support structure in the base substrate layer while the base substrate layer is heated and covering the support structure with the skin. In a third example of the method, optionally including the first and second examples, covering the support structure with the skin includes hiding the support structure from view in a vehicle cabin and indicating a location of an audio assembly, the audio assembly housed in a void of the base substrate layer, within the vehicle cabin based on a placement of the plurality of perforations.

As used in this application, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is stated. Furthermore, references to “one embodiment” or “one example” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. The terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements or a particular positional order on their objects. The following claims particularly point out subject matter from the above disclosure that is regarded as novel and non-obvious.