Many modern aircraft components are made of composite material. Forming of the composite material into a desired aircraft component may be achieved using a variety of composite manufacturing techniques, such as hand lay-up, drape forming, press forming, and automatic fiber placement (AFP). These methods may all be prone to strain and wrinkling of the composite material when forming parts having extreme curvature or complex curvatures and have various other disadvantages, as described below.
Hand lay-up is a labor intensive process and requires single ply application of multiple layers of composite material to a formed surface to form a part. Hand lay-up also involves several vacuum compaction cycles to remove trapped air and consolidate composite plies. These vacuum compaction cycles require expensive consumable materials, such as elastomeric vacuum bags, which must be discarded after the part is completed.
Drape forming or hot drape forming is a process using a vacuum chamber defined by an elastomeric material sealed around uncured composite material placed on a single form block. The uncured composite material is then heated before atmosphere is evacuated from the vacuum chamber. This causes external atmosphere to push against the elastomeric material, thereby pressing the composite material against the form block. However, this process is limited to forming only one or two flanges in the same direction simultaneously and straight or slightly-curved parts.
Press forming is a process using heavy and expensive equipment to form flanges of a composite part. Press forming generally requires two form dies, one acting as a base for the material to form to and the other die acting as a pusher. However, like drape forming, press forming is generally limited to forming only one or two flanges in the same direction simultaneously and straight or slightly-curved parts.
AFP is a process using heavy and expensive equipment to place multiple layers of individual strips of uncured composite material, such as prepreg tow, onto a form block or shape. This process is time consuming and is generally limited to forming only one or two flanges in the same direction.
Embodiments of the present invention solve the above-mentioned problems and provide a distinct advance in the art of forming a formable material into a rigid part.
One embodiment of the invention is a method of manufacturing an aircraft part from formable material, including the steps of placing the formable material on a rigid forming component, then actuating expansion of one or more inflatable components, such that the inflatable components press flange portions of the formable material against the rigid forming component. Then the method may include a step of forming the formable material while the formable material is pressed between the inflatable component and the rigid forming component.
Another embodiment of the invention is a part forming apparatus for shaping a formable material into a rigid part having angled flanges. The part forming apparatus may include two holding chambers, two rigid forming components each fixed within one of the holding chambers, a first pressure source, and at least one inflatable component. The two holding chambers may be actuatable between a first open configuration and a second closed configuration in which the two holding chambers cooperatively form a single substantially enclosed holding chamber, and the two rigid forming components may be aligned and configured to compress the forming material when the two holding chambers are in the second closed configuration with the forming material disposed between the two rigid forming components. The inflatable component may be fixed relative to at least one of the rigid forming components and at least one of the holding chambers, and may be fluidly coupled with the first pressure source for inflation thereof when the two holding chambers are in the second closed configuration.
Yet another embodiment of the invention includes a part forming apparatus for shaping a formable material into a rigid part, and includes at least one rigid forming component, at least one holding chamber, and at least one inflatable sheet sealed to the at least one holding chamber. The rigid forming component may be sized and shaped according to a desired size and shape of at least one surface of the rigid part. The inflatable sheet may be fluidly coupled with at least one pressure source for inflation thereof, and may be positioned such that, when at least partially inflated, the inflatable sheet presses toward and against the at least one rigid forming component.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the current invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.
Embodiments of the current invention are described in detail below with reference to the attached drawing figures, wherein:
The drawing figures do not limit the current invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
The following detailed description of the invention references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the current invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the current invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the current technology can include a variety of combinations and/or integrations of the embodiments described herein.
A part forming apparatus 10, constructed in accordance with embodiments of the present invention, is illustrated in
The formable material 12 may be any formable, shapeable material, such as uncured composite material, thermal plastics, aluminum, formable metals, and the like. The formable material 12 may be, for example, stacked layers of uncured composite ply or composite prepreg tow. Composite material, as is known in the art, generally includes at least two constituent components—a reinforcement material and a matrix material. The reinforcement material generally provides mechanical strengthening properties, such as high tensile strength, to the composite material, while the matrix material acts as a binder to hold the reinforcement material together. The reinforcement material and the matrix material may possess additional properties not discussed herein. Furthermore, the composite material may include additional components not discussed herein.
Examples of the reinforcement material that may be used include, but are not limited to, fiber materials such as carbon fiber, boron fiber, fiberglass, aramid fiber, ceramic fiber, and the like. In the case of fiber-based reinforcement materials, the fiber may exist in one of at least two forms—either preimpregnated (prepreg), in which the fiber may be coated with a matrix material that is uncured, such as uncured resin, or as dry fiber, with no matrix material incorporated prior to part manufacture. The matrix material may typically be in the form of polymer resins, such as epoxies, bismaleimides, vinyl esters, and the like, among others.
The rigid forming components 14,16 may be compression blocks, forming dies, plates, or any rigid surface configured to correspond with a desired shape and configuration of the composite part to be formed thereon. For example, as illustrated in
The inflatable components 18,20 may be any substantially air-tight, flexible, inflatable material with high elongation, such as an elastomeric material, silicone rubber, or the like. In some embodiments of the invention, the inflatable components 18,20 may be made of silicone rubber between 0.05 and 0.5 inches thick, or, for example, ⅛th inch thick. The inflatable components 18,20 may also be reusable after exposure to the heat required for forming the composite material. In some embodiments of the invention, the inflatable components 18,20 may comprise two hollow bladders made of inflatable material. For example, both of the two hollow bladders may be mounted in fixed relation to the first rigid forming component 14 and located at opposing sides of the first rigid forming component 14, as illustrated in
In one embodiment of the invention, as illustrated in
As illustrated in
The holding chambers 22,24 may be actuatable toward and away from each other, allowing proper placement of the formable material 12 when open, and forming a single, substantially enclosed holding chamber when closed. In some embodiments of the invention, this actuation may be provided by one of the pressure sources 26,28, as later described herein. However, other methods of actuating the holding chambers 22,24 and/or the rigid forming components 14,16 toward each other may be used without departing from the scope of the invention. In some embodiments of the invention, as illustrated in
In some embodiments of the invention, the holding chambers 22,24 may create an air-tight chamber surrounding the inflatable components 18,20, the rigid forming components 14,16, and the formable material 12. However, in other embodiments of the invention, the holding chambers 22,24 may merely be frames or support components for other elements of the part forming apparatus 10, and need not mate or form an air-tight chamber for expansion or inflation of the inflatable components 18,20.
The pressure sources 26,28 may comprise air compressors, vacuums, or other devices operable to induce a pressure differential to inflate or elongate the inflatable components 18,20. In some embodiments of the invention, the pressure sources 26,28 may include a first pressure source 26 and a second pressure source 28. The first pressure source 26 may be fluidly coupled with the inflatable components 18,20 through an opening or port, such that when the first pressure source 26 is activated, air is pumped into the inflatable components 18,20. For example, as illustrated in
The second pressure source 28 may be coupled with one of the holding chambers 22,24 and may hydraulically actuate the holding chambers 22,24 toward and/or into direct contact with each other. Additionally or alternatively, the second pressure source may be coupled with one of the rigid forming components 14,16 and may hydraulically press one of the rigid forming components 14 into the formable material 12 resting on another of the rigid forming components 16, as illustrated in
The heat source 30 may be any source of heat and may be located in any desired location on the part forming apparatus 10. For example, as illustrated in
In some embodiments of the invention, control of the moveable or actuatable components described herein may be provided by way of a control system 38, as illustrated in
In some embodiments of the invention, the control system 38 may comprise a processor and/or computer-readable memory residing thereon or communicably coupled with the processor and may be configured for performing one or more of the method steps described herein. For example, the control system 38 may include any computer and/or server, such as a desktop computer, a laptop computer, a tablet, a mobile phone, or any other computing device having a data processor and computer-readable memory. The control system 38 may include or have access to hardware and software for receiving, storing, accessing, and transmitting information. The control system 38 may also comprise a display, such as a computer monitor, and a user interface, such as a keyboard, mouse, touch screen, or the like for allowing an operator thereof to send and receive information to and from the pressure sources 26,28 or any actuation components, support components, and/or sensors associated with the part forming apparatus 10.
In some embodiments of the invention, the control system 38 may further include and/or be communicably coupled with one or more servers (not shown) running Windows; LAMP (Linux, Apache HTTP server, MySQL, and PHP/Perl/Python); Java; AJAX; NT; Novel Netware; Unix; or any other software system. The control system 38 may also include conventional web hosting operating software, searching algorithms, an Internet connection, and may be assigned a URL and corresponding domain name so that it can be accessed via the Internet in a conventional manner.
The computer-readable memory of the control system 38 may include any data storage device or computer-readable medium, as described herein. In some embodiments of the invention, some or all of the computer-readable memory may be located remotely from the processor. One or more computer programs may be stored in or on the computer-readable medium and may be configured for being executed by the processor. The computer programs may comprise computer code or listings of executable instructions for implementing logical functions in the processor and/or other devices communicably coupled therewith and can be embodied in any non-transitory computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device, and execute the instructions. In the context of this application, a “computer-readable medium” can be any non-transitory means that can contain, store, or communicate the programs. The computer-readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electro-magnetic, infrared, or semi-conductor system, apparatus, or device. More specific, although not inclusive, examples of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), a read-only memory (ROM), an erasable, programmable, read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disk read-only memory (CDROM).
In use, the rigid forming components 14,16 and their corresponding holding chambers 22,24 may be actuatable between a first open configuration, as illustrated in
A method 600 for manufacturing an aircraft part or a composite part using the part forming apparatus 10 disclosed herein will now be described in more detail, in accordance with various embodiments of the present invention. The steps of the method 600, as shown in
As illustrated in
Next, the method 600 may include a step of actuating the first rigid forming component 14 to compress the non-flange portion 36 of the formable material 12 between the first rigid forming component 14 and the second rigid forming component 16, as depicted in block 604. This actuation may be triggered by an operator or by the control system 38 described herein. As described above, one of the pressure sources 26,28 may be activated to hydraulically actuate the first rigid forming component 14 and/or its corresponding holding chamber 22 to move toward and apply pressure to the formable material 12. The amount of pressure applied may depend on requirements of the part being formed. In other embodiments of the invention, this compression of the non-flange portion 36 of the formable material 12 may be accomplished using other manual or automated techniques and devices to actuate the first rigid forming component and/or its corresponding holding chamber 22 without departing from the scope of the invention.
Subsequently or simultaneously, the method 600 may include a step of actuating expansion of at least one of the inflatable components 18,20 to press flange portions (i.e., flanges 32,34) of the formable material 12 against at least one of the rigid forming components 18,20, as depicted in block 606. So, for example, the first pressure source 26 may be turned on or otherwise activated (e.g., opening of a valve fluidly coupling the first pressure source 26 with the inflatable components 18,20) by an operator or by the control system 38 described herein, causing the inflatable components 18,20 to stretch and expand while filling up with air or any other gas. In the embodiments of the invention illustrated in
However, the inflatable components 18,20 may be mounted or otherwise fixed in any desired configuration relative to the rigid forming components 14,16 and the holding chambers 22,24. Specifically, any configuration of the inflatable components 18,20, in cooperation with any shape and configuration of the rigid forming components 14,16 and any confinement provided by the holding chambers 22,24, may be used so as to press and hold various edge portions of the formable material 12 against surfaces of one of the rigid forming components 14,16 to form any flanges of any desired size and angle. For example, this method 600 may be used to form C-shaped channel flanges, U-shaped channel flanges, single L-shaped flanges, opposing Z-shaped channel flanges, or any other flange configurations known in the art.
Finally, the method 600 may include a step of forming and/or curing the formable material 12 with the heat source 30 and/or an alternate heat source 30, as depicted in block 608, while the formable material 12 is pressed between the inflatable components 18,20 and at least one of the rigid forming components 14,16. For example, the heat source 30 may be triggered by an operator or by the control system 38 described herein to heat up to a desired forming temperature for the formable material 12 (e.g., composite cure temperature). As described above, the heat source 30 may provide heat to the formable material 12 in any way known in the art, such as IR heaters fixed to one or both of the rigid forming components 18,20 and/or one or both of the holding chambers 22,24.
Advantageously, the part forming apparatus 10 prevents undesirable wrinkling and buckling, particularly when forming arced single L flanges, opposing Z-flanges, or C flanges, as in the embodiment of the invention illustrated in
In some alternative embodiments of the invention, as illustrated in
As illustrated in
In use, the holding chambers 122,124 are actuated toward each other, creating an air-tight seal between the sheet of inflatable material 150 and each of the holding chambers 122,124. Then one of the pressure sources 126,128 may be activated to create a pressure differential between the holding chamber 122 and the holding chamber 124. This may be accomplished via vacuum of atmosphere in the holding chamber 124 and/or via air forced into holding chamber 122 (via one of the pressure sources 126,128), inflating the inflatable material 150 in a direction toward the holding chamber 124, thereby bending portions of the formable material 112 into two flanges 132,134.
In yet another alternative embodiment of the invention, as illustrated in
However, in this embodiment of the invention, as illustrated in
During inflation in
In yet another alternative embodiment of the invention, as illustrated in
Although the invention has been described with reference to the embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
Number | Name | Date | Kind |
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2375599 | Walton | May 1945 | A |
2787973 | Heidmann | Apr 1957 | A |
3670546 | De La Sierra | Jun 1972 | A |
3698337 | Brawner | Oct 1972 | A |
6779374 | Roldan | Aug 2004 | B1 |
20130160512 | Chen | Jun 2013 | A1 |
Number | Date | Country | |
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20170182540 A1 | Jun 2017 | US |