The invention relates to a method of positioning and holding one or more stacked sheets of air permeable media or filtration media within a molding tool prior, continuing to hold the media in place during encapsulation with a plastic resin, thereby reliably positioning and encapsulating the media in an efficient means into a molded frame formed directly onto the media, forming a unitary encapsulated product. Also disclosed is a hydrocarbon adsorption trap manufactured by this method.
In the art it is known to provide a frame to mount a filter media in a housing and to support the filter media. It is also known to produce a filtration device by separately producing a frame member configured to receive the media and then gluing filter media into the frame member to form the intended filter element or device product.
It is known to produce air permeable media sheets have open pores sized to capture or restrict the passage of particle or contaminants for filtering fluids or as well as using air permeable sheets to enclose hydrocarbon adsorption media having hydrocarbon adsorption properties.
Regarding hydrocarbon adsorption media and HCA traps, it is desirable to trap evaporated fuel and oil vapors within the air intake system, thereby preventing their release into the outside environment. Fuel vapors contain hydrocarbons which are known to be a significant contributing component in urban smog.
Gasoline, for example, is a highly volatile hydrocarbon fuel that includes components which transition easily from a liquid to vapor phase. Elevated temperatures such as occurring during normal internal combustion engine operation accelerate the liquid to vapor transition. The hydrocarbon vapors, unless treated or captured, may ultimately discharge into the atmosphere. It is known that hydrocarbon vapors are discharged from the engine crankcase during engine operation. When the engine is shutdown, these vapors may continue to be released from the hot engine crankcase and other components, particularly as the engine cools.
The control of hydrocarbon vapors escaping into the environment is regulated by state and federal regulations. Hydrocarbon traps for capturing hydrocarbon vapors are well known. For example, motor vehicles are commonly equipped with hydrocarbon adsorptive emissions canisters connected to the fuel tank for trapping hydrocarbon vapors, particularly as emitted during refueling.
It is known that certain porous materials such as activated carbon are useful for absorption and removal of organic hydrocarbon vapors. It is known hydrocarbon vapors are liquefied within small micro pores of the activated carbon and may be retained by absorption.
It is known in the state of the art to produce a hydrocarbon adsorption (HCA) media, such as two adjacent sheets of air permeable media between which hydrocarbon adsorptive materials are arranged. It is known to arrange such HCA media in an air intake system of an internal combustion engine where it is operable to entrap hydrocarbon vapors.
As a general introduction to the art of injection molding-injection molding is a manufacturing process for producing parts by injecting thermoplastic, thermosetting polymers, plastic or resin materials into a mold tool. Common polymers like epoxy and phenolic are some examples of thermosetting plastics while nylon, polyethylene, and polystyrene are examples of thermoplastic materials.
Injection molding machines generally consist of a material hopper, an injection ram or screw-type plunger, and a heating unit. Also known as presses, they hold the molds in which the final components are shaped. Presses are typically rated by tonnage, which expresses the amount of clamping force that the machine can exert. This force keeps the mold closed during the injection process, which may involve high pressures in the plastic injection process to completely fill the mold cavity.
The mold may consist of two primary mold halves, the injection mold plate and the ejector mold plate. Plastic resin may enter the mold through a sprue or gate in the injection mold; the sprue bushing is to seal tightly against the nozzle of the injection barrel of the molding machine and to guide/direct molten plastic to flow from the barrel into the mold, also known as the mold cavity. The sprue bushing directs the molten plastic to the cavity through channels that are machined into the faces of the mold plates. These channels allow plastic to run along them. The channels may also be called runners. The molten plastic flows through the runners and into the cavity geometry to form the desired part.
Typically in the state of art, the material for the part is fed into a heated barrel, mixed, and forced into a mold cavity, where it cools and hardens to the configuration of the cavity, thereby forming the desired part or component. The mold with the cavity is often shaped and designed from metal, typically either steel or aluminum, and precision-machined to form the features of the part to be molded.
The mold closes enclosing the mold cavity therein. When parts are molded, typically pelletized raw material may be fed through a hopper into a heated barrel with a reciprocating screw. The material is forced at high pressure into the part forming mold cavity. Once the material within the mold cools so that the molded part is dimensionally stable, the mold opens and the molded dimensionally stable part may be removed from the mold and the process restarted.
An object of the invention is to provide a method and apparatus to accurately position one or more sheets (stacked sheets) of an air permeable media, such as a filtration media, within a mold tool and to provide a retractable media location enforcement means within the mold tool to locate the media and hold the location of the media at a desired location within the tool, as well as second media holding means operable to engage and continue to hold the media in the position within the mold after the retractable location enforcement means are retracted, and continue holding during the plastic resin encapsulation process.
According to the present inventive disclosure, an innovative injection molding process is advantageously utilized to manufacture filter elements or hydrocarbon adsorption traps, such as the exemplary types and configurations disclosed herein. Advantageously, the present inventive disclosure discloses method of positioning/fixing location and loosely stacking filter media sheets or HCA media sheets in a mold tool, wherein the tool includes locating components operable to fix the location of the media within the mold tool to a desired position during media loading into the tool, closing of the tool and subsequent injection molding. Advantageously, the present inventive disclosure teaches methods of locating and molding a frame around the periphery of the media sheets, holding the media sheets in the mold tools while automatically retracting media positioning/locating components before molding, and then molding the frame around the periphery media sheets to form the desired filter product or HCA trap as a single, one-piece, integrally molded component.
Advantageously in the invention, the present methods located the media within the mold and maintain the required position before and during frame molding, advantageously deleting other secondary steps practiced in the art including gluing the media and further producing a separate frame component and then assembling the frame to the glued media. As such, the specially modified injection molding process disclosed herein is advantageously utilized to manufacture filter elements or hydrocarbon adsorption traps in an automated, efficient, repeatable, reliable and low cost way, while eliminating additional steps of the prior art.
The accompanying Figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Features of the present invention, which are believed to be novel, are set forth in the drawings and more particularly in the appended claims. The invention, together with the further objects and advantages thereof, may be best understood with reference to the following description, taken in conjunction with the accompanying drawings. The drawings show a form of the invention that is presently preferred; however, the invention is not limited to the precise arrangement shown in the drawings.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of apparatus components related to a filter apparatus. Accordingly, the apparatus components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
In one exemplary embodiment for enablement and illustration of the disclosed method of producing an encapsulated filter device of one or more sheet of air permeable filtration media,
In the exemplary embodiment of the HCA trap, the HCA media sheet 12 may include a first hydrocarbon vapor permeable media retention layer 16, a second hydrocarbon vapor permeable media retention layer 18 preferably positioned in a spaced parallel relationship to the first layer forming a gap 22 therebetween and a hydrocarbon vapor adsorbent media 20 disposed in the gap 22 between the first 16 and second 18 layers for adsorbing hydrocarbon laden vapors, for example evaporated fuel vapors from the intake tract when the engine is not operating.
In some embodiments of the HCA media sheet 12, the spaced media retention layers 16 and 18 may be secured together or closed/joined together along the periphery edge 74 of the media sheet 12 to seal the gap 22 at the layer edge portions 74 to retain the adsorbent media 20 between the layers 16 and 18, thereby preventing the hydrocarbon vapor adsorbent media 20 from escaping the gap 22 between the media retention layers 16 and 18.
In a preferred embodiment of the HCA media sheet 12, the edge portions of the spaced media retention layers 16 and 18 may be remain open, then relying upon the modified injection molding process of the present invention to seal the seal the edge portions of the spaced media retention layers 16 and 18 with the injection molded support frame 14, thereby preventing the hydrocarbon vapor adsorbent media 20 from escaping the gap 22 between the media retention layers 16 and 18.
In another preferred embodiment of the HCA media sheet 12, the edge portions of the spaced media retention layers 16 and 18 may be open with the hydrocarbon vapor adsorbent media 20 secured in the gap 22 between the media retention layers 16 and 18 with an adhesive material 24, thereby holding the hydrocarbon vapor adsorbent media 20 within the gap 22 at least until finally sealed within by the injection molded support frame 14 molded onto the peripheral edges of the HCA media sheet 12. The media retention layers with the adhesive bound hydrocarbon vapor adsorbent media may form a substantially rigid flat sheet, the substantially rigid sheet having sufficient rigidity to be self supporting, maintaining the sheet in a flat sheet form when supported only at the peripheral circumferential edges of the sheet.
The hydrocarbon adsorbent media 20 is preferably a hydrocarbon absorptive material, examples of which include activated carbon, zeolite, or other known hydrocarbon vapor absorptive materials.
In preferred aspects of the HCA media sheet 12, the hydrocarbon adsorbent media 20 includes activated carbon granules.
In preferred aspects of the HCA media sheet 12, the hydrocarbon adsorbent granules 20 may be bound together by an adhesive 24, the adhesive 24 maintaining the granules 20 in a desired spaced distribution between the spaced media retention layers 16 and 18 and optionally in a preferred shape or form (such as in a sheet form 12 of substantially uniform thickness (substantially uniform spacing between the spaced media retention layers 16 and 18).
The hydrocarbon vapor permeable layers (or air permeable layers) 16 and/or 18 may be realized as woven or non-woven synthetic fiber layers, for example polyester fiber layers. In some embodiments the air permeable layers 16 and/or 18 may be realized as synthetic nonwoven fiber sheets. Nonwoven fabrics may be manufactured, in multiple forms, from many grades of cellulose and most natural and synthetic fibers. Fibers used may include polyester, polypropylene, glass, acrylics, rayon, nylon, cotton, fluoropolymers and a host of others fiber materials select due to their special material compatibility for particular applications, such as selection for heat, hydrocarbon and fuel vapor exposure compatibility.
As shown in
Showing the process by example,
The peripheral support frame 14 provides support to the filter media sheet(s) or (for example) hydrocarbon adsorption media sheets 12, at least along the peripheral edges of the sheets, to mount the hydrocarbon adsorption media sheet or sheets 12 onto, for example, an insides surface of an air duct, or an air intake tract, or into the interior of a filter housing, although the hydrocarbon adsorption trap according to this disclosure may be installed to other components or used in other applications.
In the exemplary embodiment illustrated in
In
As schematically shown in
One or more pusher members 50 may be provided extending slideably through the lower press portion 44 and operable to move the positioning pin retraction member 52 to retract the media position holding pins 34 when the mold tool halves 36 and 38 close (see
The pusher members 50 may be urged to move in a downward direction 54 (direction according to arrow 54 in
Movement of the pusher members 50 in the downward direction 54 urges the positioning pin retraction member 52 in a downwards direction 54, thereby urging the media position holding pins 36 to retract away from the media sheets 12 and to retract substantially from the interior of the mold cavity 46 (see
According to the invention it is preferred that the first mold tool half 36 and the second mold tool half 38 include complimentary media fixation walls 56, having complimentary shape and axial alignment and projecting axially from the old tool halves to engage directly and in an aligned fashion against opposing sides of the filter media or HCA media sheet 12, thereby to compress the media sheets 12 together. One or both of the first 36 and second 38 mold halves may be realized as mold inserts, moveably mounted and located by tool compression springs 40, the tool compression springs 40 compressively loading and urging the first 36 and second 38 mold halves together, the spring loading maintaining a sufficient compressive force on the media fixation walls 56 holding the media sheet(s) 12 in the desired position in the mold so the retracting media position holding pins 34 can retracted without losing the media positioning in the mold. The media fixation walls 56 may also serve as injection resin boundary walls closing the radial inward side of the mold cavity 46 from the open faces 58, thereby preventing resin in the mold cavity from reaching and contaminating the open faces 58 of the media sheet(s).
According to the invention it is preferable that the media position holding pins 36 are not fully retracted away from the media sheets 12 until the media fixation walls 56 contact and begin to compress the media sheets 12 together, the compression thereby holding the media sheets 12 in the desired position in the mold tool so the media position holding pins 36 are no longer required and may be safely retracted.
The media fixation walls 56 may compress the media sheets 12 with substantial force, a sufficient force of the media fixation walls 56 pressing sealably against the opposing sides of the media to thereby close the radial inner side of the mold cavity preventing the to be injected plastic resin material forming the peripheral support frame 12 from migrating into or onto the open central portion of the encapsulated filtration product or alternately the HCA trap 10, so that the open faces 58 of the media sheet(s) 12 remain open and unobstructed by the injected plastic resin after the injection molding operation.
The first mold half 36 and/or the second mold half 38 may including channels 64 machined into the faces of the first mold half 36 and/or the second mold half 38, the channels conducting injected plastic resin into the mold cavity 46.
In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
This application claims the benefit of U.S. Provisional Application No. 62/073,985, filed Nov. 1, 2014.
Number | Date | Country | |
---|---|---|---|
62073985 | Nov 2014 | US |