Acoustic component and method and apparatus for producing same

According to embodiments described in the specification, a method and apparatus are provided for producing an acoustic component. The acoustic component comprises a first compression-molded member comprising a first material; and a second injection-molded member coupled to and substantially surrounding the first member, the second member comprising a second material.

FIELD

The specification relates generally to acoustic components, and specifically to an acoustic component and methods and apparatuses for producing acoustic components.

BACKGROUND

Motor vehicles, and indeed a wide selection of other machinery, include various sources of vibration, both audible and inaudible. Reducing the impact of such vibration on the machinery itself, associated machinery and the users thereof presents challenges relating to both the design and the manufacturing of components for such machinery.

DETAILED DESCRIPTION OF THE EMBODIMENTS

According to an aspect of the specification, an acoustic component is provided, comprising a first compression-molded member comprising a first material; and a second injection-molded member coupled to and substantially surrounding the first member, the second member comprising a second material.

According to another aspect of the specification, an apparatus is provided for producing an acoustic component, the apparatus comprising: a core portion and a cavity portion, the core and cavity portions having an open position and a closed position in which the core portion is matingly received by the cavity portion; the core portion comprising an injection area and a compression area, the compression area for receiving an insert of a first material in the open position; the cavity portion comprising a mating injection area and a mating compression area, wherein the mating injection area lies adjacent to the injection area for defining an injection channel for receiving a second material in the closed position, and wherein the mating compression area lies adjacent to the compression area in the closed position for defining a compression chamber; at least one of the compression area and the mating compression area comprising a heater; at least one of the injection area and the mating injection area comprising a cooler; the injection area, mating injection area, compression area and mating compression area being configured for substantially simultaneous operation.

According to a further aspect of the specification, a method of producing an acoustic component is provided, the method comprising: receiving an insert of a first material in one of a core portion and a cavity portion, the core portion and cavity portion being in an open position; transitioning the core portion and the cavity portion to a closed position in which the cavity portion matingly receives the core portion to define a compression chamber containing the insert, and an injection chamber; activating a first controller for injecting a second material into the injection chamber, and a second controller for heating the compression chamber.

Referring now toFIG. 1, views of an example acoustic component, in the form of a wheel liner100, are depicted. Although wheel liner100is provided as an exemplary acoustic component, a wide variety of acoustic components having both automotive applications (including those other than wheel liners) and non-automotive applications are contemplated. Examples of such additional acoustic components will become apparent to those skilled in the art throughout this specification.

Wheel liner100includes a first compression molded member104-1and a second injection molded member108. As seen inFIG. 1C, wheel liner100also includes a third compression molded member104-2. In general, wheel liner100includes at least one compression molded member, and any suitable number of compression molded members can be incorporated into wheel liner100.

Compression molded members104-1and104-2(collectively referred to as compression molded members104, and generically referred to as a compression molded member104) comprise a first material or plurality of materials. In general, compression molded members104are constructed at least partly of heat- and pressure-sensitive materials which cures in the presence and heat, pressure or both heat and pressure (i.e. thermoset materials). In the present example embodiment, a fabric substrate is used for compression molded members104.

Turning briefly toFIG. 2, a schematic exploded view of a compression molded member104prior to compression and heating is depicted. Compression molded member104thus includes a plurality of layers of material. In the present example embodiment, compression molded member104includes a first (or top) layer200, a second (or middle) layer204and a third (or bottom) layer208. The first and third layers200and208are selected for vibration and noise absorption properties and to meet specific harmonics or noise level requirements, based on the application of the resulting wheel liner100. It is also contemplated that first and third layers200and208can be replaced with multiple layers of material, depending on the requirements of the particular acoustic component. Examples of materials for the first and third layers200and208includes polyester fabrics and nylon cloth materials.

Second layer204comprises a heat sensitive polymer to which first and third layers200and208are laminated. Second layer204can include, for example, materials such as polypropylene, nylon or any other suitable heat sensitive thermoset material.

Returning toFIGS. 1A-1D, injection molded member108is coupled to, and substantially surrounds, compression molded members104. Injection molded member includes a second material. The second material includes a flowable polymer such as polypropylene. It will now be apparent to those skilled in the art that a variety other suitable polymers can also be employed. In general, the second material is suitable for injection molding to form injection molded member108.

Injection molded member108provides a substantially rigid frame for supporting compression molded members104and retaining the desired geometry of wheel liner100. Injection molded member108can also include attachment points, such as opening112seen inFIG. 1A, for receiving fasteners to secure wheel liner100to an automobile or other vehicle.

As seen inFIG. 1B, injection molded member108can also define a living hinge area116at which wheel liner100can bend. Turning briefly toFIG. 3, wheel liner100is shown in the flexed or bent position, in which injection molded member108bends at hinge area116, for example to allow for installation of wheel liner100in an automobile.

It is also contemplated that in some embodiments, living hinge area116can be provided in part by compression molded members104. In such embodiments, compression molded members104-1and104-2can be replaced by a single compression molded member104which traverses both “halves” of injection molded member108, thus crossing through living hinge area116within the material of injection molded member108.

As seen inFIGS. 1A-1DandFIG. 3, each compression molded member104is coupled to injection molded member108by overmolding of member108onto members104during the injection molding of member108. Members104thus become bonded to member108. Further, compression molded members104and injection molded member108are molded substantially simultaneously. That is, wheel liner100, during its manufacture, is subject to both injection and compression molding processes during a single molding cycle, as will be discussed in greater detail below in connection with example embodiments of the apparatus used to manufacture wheel liner100(and other acoustic components).

Referring now toFIG. 4, a schematic diagram of an apparatus400for manufacturing wheel lining100and other acoustic components is shown. Apparatus400includes a core portion404and a cavity portion408. Core and cavity portions404and408have an open position and a closed position relative to each other. In the open position, as depicted inFIG. 4, core and cavity portions404and408are separated from each other by a certain distance, labelled “D”, in order to allow for loading of materials, servicing and the like. Appropriate distances of separation will occur to those skilled in the art through the course of this description. More generally, in the open position, core portion404and cavity portion408are not sealed together. In the closed position, which will be discussed in further detail below, core portion404is matingly received by cavity portion408, and core portion404and cavity portion408are reversibly sealed together.

Core portion404includes an injection area412and a compression area416. It is noted that while injection area412is labelled twice inFIG. 4, injection area412is in fact a single injection area surrounding compression area416, seen in cross-section inFIG. 4. In other embodiments, multiple separate injection areas can be provided as necessary for the particular acoustic component being manufactured. Cavity portion408includes a mating injection area420and a mating compression area424. The above-mentioned areas will also be discussed below in further detail in conjunction with the closed position of core portion404and cavity portion408.

Apparatus400further includes one or more coolers and one or more heaters. In the present example embodiment, core portion404includes a cooler428(as with injection area412, cooler428can be a loop, seen twice in cross section inFIG. 4) and a heater432. As seen inFIG. 4, cooler428is adjacent to injection area412, and heater432is adjacent to compression area416. Cavity portion408also includes a cooler436adjacent to mating injection area420, and a heater440adjacent to mating compression area424. It is contemplated that in other embodiments, coolers and heaters may be present in only one of core portion404and cavity portion408.

Coolers428and436are not particularly limited, and can include any suitable cooling mechanisms, such as cooled fluid circuits. Heaters432and440are likewise not particularly limited, and can include any suitable heating mechanisms, such as electric (resistive) elements, heated fluid circuits and the like. In general, the materials of core and cavity portions404and408can include thermally conductive materials between the injection and compression areas and the coolers and heaters, respectively. The materials of core and cavity portions404and408can further include layers of insulating materials (not shown) between the heaters and coolers, and between the injection and compression areas.

In some embodiments, the sections of core portion404and cavity portion408which define compression area416and mating compression area424can be provided in the form of compression molding inserts which are removable from the remainder of the core and cavity portions. Thus, different compression molding inserts can be coupled to core and cavity portions404and408to accommodate different shapes, thicknesses and materials for the compression molded members of acoustic components. Such compression molding inserts can also carry heaters432and440.

In addition, apparatus400includes a first controller444connected with coolers428and436, and a second controller448connected with heaters432and440. The nature of controllers444and448are not particularly limited. For example, controllers444and448can include any of a wide variety of digital controllers, Application-Specific Integrated Circuits (ASICs) and the like. In some embodiments, controllers444and448can be implemented on a computing device such as a desktop computer having a processor, a memory and input/output devices (e.g. a keyboard and mouse). In such embodiments, controllers444and448can be implemented as one or more applications stored in the memory and executed by the processor. In general, controller444controls coolers428and436, and can also control the injection of flowable polymer, while controller448controls heaters432and440.

Turning now toFIG. 5, an example core portion404is shown, configured for manufacturing wheel liner100, discussed earlier. Core portion404thus includes injection area412and compression area416. As seen inFIG. 5, two compression areas416are shown, for accommodating the first and third members104-1and104-2of wheel liner100. Injection area412surrounds the two compression areas416. Also included in cavity portion408are slide features500for forming undercuts in wheel liner100. It will be appreciated that slide features500need not necessarily be present, or can be present in different numbers and configurations. Core portion404further includes apertures504for coupling and sealing core portion404to cavity portion408.

Referring toFIG. 6, an example cavity portion408, corresponding to core portion404as shown inFIG. 5, is shown as configured for manufacturing wheel liner100. Thus, injection area420is shown surrounding two compression areas424. Fasteners600are also shown, for cooperating with apertures504in sealing core portion404and cavity portion408together. It can be seen fromFIGS. 5 and 6that when core portion404and cavity portion408are placed adjacent to each other and coupled, core portion404(and particularly injection area412and compression areas416thereof) is received by, and mates with, cavity portion408. Also shown inFIG. 6is an injection inlet602for delivering the injection polymer to injection area412. Additional injection inlets602can be provided if suitable. It is contemplated that some injection inlets602can be used to deliver injection polymer, while others can be used to deliver cooling fluid to cooler428.

Turning toFIG. 7, a simplified schematic diagram of core portion404and cavity portion408in the closed position is shown. In the closed position, core portion404and cavity portion408are coupled adjacent to one another, for example by way of fasteners600and apertures500. In the closed position, injection area412and mating injection area420lie adjacent to form an injection channel700. Compression area416and mating compression area424also lie adjacent to one another for defining a compression chamber704(or, in the example embodiment ofFIGS. 5 and 6for producing wheel liner100, two compression chambers).

Also shown inFIG. 7is a seal-off area708between injection channel700and compression chamber704. Seal-off area708, when a fabric substrate is inserted in compression chamber704, acts to isolate injection channel700from compression chamber704, with a portion of the fabric substrate protruding into injection channel700for overmolding.

From the above description, a method of producing an acoustic component will now be apparent, as will be discussed below.

In use, core portion404is equipped with an appropriate compression molding insert having the desired configuration (i.e. shape, depth and the like), and heater432. Core portion404then receives, in the open position, a fabric insert as discussed above in connection with wheel liner100. To that end, the fabric insert can include mounting holes, tabs, slots and the like for cooperating with corresponding protrusions, pins and the like on core portion404for accurately locating the fabric insert and maintaining the fabric insert in position while core portion404and cavity portion408are moved to the closed position. In the present example embodiment, at least one of core portion404and cavity portion408include retractable pins which are received through mounting holes near the edge of the fabric insert. Once apparatus400is in the closed position, the pins can retract such that the mounting holes are filled with injection molding material, thus advantageously substantially preventing the transfer of noise, water, dirt or other foreign materials from one side of the acoustic component to the other.

Turning briefly toFIG. 6, a plurality of channels into which mounting pins can retract are shown at604. Any suitable number of such pins and channels604can be provided in either one of core portion404and cavity portion408. It is also contemplated that the fabric substrate can be placed in cavity portion408in the open position, rather than in core portion404.

Turning toFIG. 8A, top and front views of wheel liner100are shown, with mounting holes indicated at800in compression members104-1and104-2.FIG. 8Bdepicts the insertion of mounting pins804into mounting holes800to locate the fabric insert and hold the fabric insert in position.

Following the closing of apparatus400, controllers444and448can be activated, substantially simultaneously, to inject flowable polymer into injection channel700while cooling injection channel700, and to heat compression chamber704. Thus, the different areas of apparatus400are configured for substantially simultaneous operation in two modes (injection and compression molding), with two separately controllable sets of operating conditions (such as operating temperature).

Once the mold cycle is complete, apparatus400can be returned to the open position for retrieval of the completed acoustic component (such as wheel liner100).

Referring now toFIG. 9, an example variation of wheel liner100is shown. In particular,FIG. 9shows a wheel liner900having a first compression molded member904-1similar to member104-1described above, and a second injection molded member908similar to memory108described above. An opening912(similar to opening112) is also shown.

Wheel liner900also includes an access door914. Access door914is openable to provide an access opening through member904-1. Such an opening can be used, for example, to access and replace indicator lights of an automobile in which wheel liner900is installed. Further discussion of access door914will be provided in connection withFIGS. 10A and 10B.

Turning toFIG. 10A, access door914is shown in an open position. When in the open position, access door914reveals an access opening1000extending through member904-1. As seen inFIG. 10A, access door914is formed of the same material as member904-1, and is joined with the remainder of member904-1. In other words, access door914can be cut from the material which forms member904-1(such as the material shown inFIG. 2). Also seen inFIG. 10Ais a support frame1004for access door914, and a lock member1008. Support frame1004and lock member1008are formed from the second material (e.g. the injection molded material) discussed above, and not from the same material as access door914.

Lock member1008is configured to releasably fit through a die-cut slot1012in access door914. In particular, locking member1008has at least one dimension that is larger than a corresponding dimension of slot1012(in the present example, the width of lock member1008is greater than the width of slot1012). However, lock member1008can still be inserted through slot1012and removed from slot1012, when sufficient force is applied, as a result of the flexibility of the material of access door914.

FIG. 10Bshows access door914in the closed position, obstructing opening1000. In the closed position, lock member1008extends through slot1012, thus retaining access door914in the closed position until sufficient force is applied to access door914to dislodge lock member1008. Such force can be applied, for example, to one or more pry slots1016defined by support frame1004. Pry slots1016allow an object (e.g. a finger, a screwdriver, and the like) to be inserted underneath access door914for applying force to open access door914.

It is contemplated that access door914and support frame1004can be produced in the same process as the remainder of wheel liner900. That is, the molds discussed above can include supplementary injection molding channels for support frame1004and lock member1008. The molds can also include means for cutting access door914from wheel liner900. In other embodiments, access door914can be pre-cut before the compression-molding material for member904-1is inserted in the molds.

Various advantages to the above methods, system and apparatus will now occur to those skilled in the art. For example, the single-cycle production of an acoustic component (including accessories such as access door914) reduces the need for post-processing or separate manufacturing of the compression and injection members104and108, while providing additional noise frequency reductions and reduced noise harmonics in the vehicle or other machinery during operation. Other advantages will now also occur to those skilled in the art.

Persons skilled in the art will appreciate that there are yet more alternative implementations and modifications possible for implementing the embodiments, and that the above implementations and examples are only illustrations of one or more embodiments. The scope, therefore, is only to be limited by the claims appended hereto.