Patent Application
20170129195
The disclosure relates to the field of manufacturing, and in particular, to composite vacuum bag manufacturing processes.
Many composite products (e.g., carbon fiber products, such as aircraft wings) are manufactured via vacuum bag manufacturing processes. Using these techniques, layers of material are placed onto each other, and are cured to harden into a composite part. In order to ensure that the layers harden into the correct shape, the layers are placed within a vacuum bag. The vacuum bag applies pressure to contour and consolidate the layers against the surface of a working tool, and to remove volatile compounds present within the layers.
As a part of this process, components known as breathers are placed proximate to the composite product. These breathers provide a passageway for air and gaseous volatiles to exit the vacuum bag. However, the industry continues to seek out enhanced designs for breathers that decrease cost and/or increase quality.
Embodiments described herein include enhanced edge breathers for composite parts. In particular, the edge breathers are designed as truss-like frames that define open channels for air to flow through. These frames are also capable of bearing load from a vacuum bag during curing of a product (e.g., at 90 pounds per square inch (PSI), in an autoclave), and without damaging the vacuum bag.
One exemplary embodiment is an edge breather for composite manufacturing. The edge breather is formed of a rigid material and includes an elongated body having a top open structure with a cross section that defines an arch. The edge breather also includes hollow passageways within the elongated body that are underneath the top structure and travel along a length of the elongated body. The top open structure defines multiple openings forming an open mesh through which air may enter.
Another exemplary embodiment is an edge breather for composite manufacturing, formed of a rigid material. The edge breather includes an elongated body having a top open structure with a cross section that defines an arch. Hollow passageways within the elongated body are underneath the top structure and travel along a length of the elongated body. The top open structure defines multiple openings forming an open mesh through which air may enter.
Another embodiment is a composite manufacturing system. The system includes a rigid tool, and an edge breather atop the rigid tool. The edge breather includes a base and a plurality of support members protruding from the base. The edge breather further includes a plurality of lateral members interconnecting portions of the support members that are distal from the base, forming a patterned structure over the base. The system also includes a surface breather laid atop the edge breather, and a vacuum bag sealing the edge breather, the surface breather, and a portion of the tool from surrounding atmosphere.
A further embodiment is method for manufacturing a composite product. The method includes placing a composite charge on a tool, locating edge breathers along the perimeter of the charge, and creating a vacuum chamber around the charge and edge breathers. The method further includes drawing a vacuum in the vacuum chamber, and drawing gases from the composite charge past a support member protruding from a base of the edge breathers.
A further embodiment is a method for fabricating an edge breather. The method includes heating a structural material into a liquid, laying the liquid to form a base, and waiting for the base to solidify. The method further includes laying the liquid iteratively in a pattern to form a plurality of support members protruding from the base, each support member comprising a portion proximate to the base and a portion distal from the base, and laying the liquid in a pattern to form a plurality of lateral members interconnecting the distal portions of the support members, forming an open patterned structure above the base. Additionally, the method comprises waiting for the liquid to solidify into a completed edge breather.
A further embodiment comprises an edge breather for composite manufacturing. The edge breather includes an arcuate, rigid open patterned structure, comprising a plurality of interconnecting lateral members, through which gas is freely capable of flowing into and out of during a vacuum bag composite manufacturing process.
Other exemplary embodiments (e.g., methods and computer-readable media relating to the foregoing embodiments) may be described below. The features, functions, and advantages that have been discussed can be achieved independently in various embodiments or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings.
Some embodiments of the present disclosure are now described, by way of example only, and with reference to the accompanying drawings. The same reference number represents the same element or the same type of element on all drawings.
The figures and the following description illustrate specific exemplary embodiments of the disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within the scope of the disclosure. Furthermore, any examples described herein are intended to aid in understanding the principles of the disclosure, and are to be construed as being without limitation to such specifically recited examples and conditions. As a result, the disclosure is not limited to the specific embodiments or examples described below, but by the claims and their equivalents.
In this embodiment, system 100 includes rigid tool 110, which forms a surface about which part 140 conforms to during manufacturing. As shown in
While in operation in one embodiment, compressor 170 may generate about one atmosphere of negative pressure on vacuum bag 120. This presses vacuum bag 120 against part 140 to conform part 140 to tool 110. This also causes vacuum bag 120 to tightly conform to the edge breathers (130, 132, 134, 136). This provides a benefit in holding part 140 tightly against the contours of tool 110 as part 140 cures, and also provides a benefit in that it rapidly draws out volatile gases and air bubbles that would otherwise be formed during the curing process. The curing process itself may further involve the application of substantial amounts of pressure and/or heat. Edge breathers (130, 132, 134, 136) of system 100 have been enhanced to exhibit a geometry that resists collapse under the pressure applied by vacuum hose 160. Further details of the edge breathers (130, 132, 134, 136) will be described with regard to
In
According to
The process of adding and curing a lay up onto to part 140 as shown in
Illustrative details of the operation of system 100 will be discussed with regard to
According to
According to
One or more flow meters 890 may be coupled with edge breather 132, either internally within edge breather 132, or in between edge breathers (e.g., 130, 132, 134, and 136 as shown in
Structure 830 is itself rigid, and is made up of multiple rigid lateral/longitudinal members 832 that interweave between support members 820, while structure 840 is made up of multiple lateral members 842 that interconnect support members 820. Lateral members 832 and 842 are fixed to support members 820 at portions 822 which are distal from base 810, as opposed to portions 824 which are proximate to base 810. In short, in one embodiment the radius of the arc defined by structure 830 is greater than the radius of the arc defined by structure 840. The spaces between structures 830 and 840 are subdivided into cells 870, in which excess resin used for curing a part (e.g., part 140) may accumulate within without substantially interfering with airflow through passageways 892 and 894 (into the page and along the length of edge breather 132). As used herein, structures 830 and 840 are described as rigid in that their cross sectional strength against compression is substantial (e.g., capable of resisting 90 PSI loads and substantial heat). That being said, when an edge breather 132 exhibits a geometry that is substantially narrow (e.g., less than half an inch) and substantially long (e.g., many feet), it may still be flexible to some degree along its length.
A wall 860 defines a hollow cylindrical tunnel 864 that runs through/along the length of edge breather 132 (i.e., in a longitudinal direction), proximate to center 814 of base 810. In this embodiment, wiring 862 for a flow meter (e.g., flow meter 890 of
While under load, edge breather 132 distributes forces in a similar manner to a truss or space frame, in that compressing loads are applied to support members 820 and 850, while at least some lateral members 832 and/or 842 receive tensile loads (other lateral members 832 and 842 may be placed in compression). This is, under load at edge breather 132 at least some of lateral members 832 and/or 842 are placed in tension while support members 820 and 850 are placed in compression.
The edge breather 132 shown an illustrated in
Edge breather 132 may be manufactured via any suitable process, such as via 3D printing, utilizing soluble core fabrication processes, polyjet manufacturing, Stereolithography (SLA), Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), Electronic Beam Melting (EBM), lost wax casting, soluble core molding, etc. For example, in one embodiment, an edge breather (130, 132, 134, 136) is a single integral three dimensional (3D) printed part that is composed of a photopolymer of acrylic urethane. Such an embodiment may be particularly resistant to crushing and therefore may be re-usable in nature. In a still further embodiment, each edge breather (130, 132, 134, 136) comprises base 810, and one or more open structures (830, 840), but does not include any supports 820 or 850. In such an embodiment, each edge breather (130, 132, 134, 136) relies on the compression resistance of the arcing shape of the open structures (830, 840) to resist compression from a vacuum bag (e.g., 120). In yet another further embodiment, tunnel 960 may be absent, and any number of patterns for open structures may be defined for an edge breather (130, 132, 134, 136).
Referring more particularly to the drawings, embodiments of the disclosure may be described in the context of an aircraft manufacturing and service method 1300 as shown in
In one embodiment, part 140 comprises a portion of airframe 118, and is manufactured during component and subassembly manufacturing 1308 via the use of edge breathers 130, 132, 134, and 136. Part 140 may then be assembled into an aircraft in system integration 1310, and then be utilized in service 1314 until wear renders part 140 unusable. Then, in maintenance and service 1316, part 140 may be discarded and replaced with a newly manufactured part 140. Edge breathers (130, 132, 134, 136) may be utilized throughout component and subassembly manufacturing 1308 in order to manufacture part 140. Edge breathers (130, 132, 134, 136) may even potentially be utilized for maintenance and service 1316 in order to repair or refurbish worn or damaged parts 140.
Each of the processes of method 1300 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include without limitation any number of aircraft manufacturers and major-system subcontractors; a third party may include without limitation any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.
As shown in
Apparatus and methods embodied herein may be employed during any one or more of the stages of the production and service method 1300. For example, components or subassemblies corresponding to production stage 1308 may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft 1302 is in service. Also, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized during the production stages 1308 and 1310, for example, by substantially expediting assembly of or reducing the cost of an aircraft 1302. Similarly, one or more of apparatus embodiments, method embodiments, or a combination thereof may be utilized while the aircraft 1302 is in service, for example and without limitation, to maintenance and service 1316.
Any of the various operations described herein may be managed/controlled by computer-controllable elements implemented as hardware, software, firmware, or some combination of these. For example, the operations of vacuum pump 170 or a robot arm (not shown) may be controlled by dedicated internal hardware. Dedicated hardware elements may be referred to as “processors”, “controllers”, or some similar terminology. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, a network processor, application specific integrated circuit (ASIC) or other circuitry, field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), non-volatile storage, logic, or some other physical hardware component or module.
Also, an element may be implemented as instructions executable by a processor or a computer to perform the functions of the element. Some examples of instructions are software, program code, and firmware. The instructions are operational when executed by the processor to direct the processor to perform the functions of the element. The instructions may be stored on storage devices that are readable by the processor. Some examples of the storage devices are digital or solid-state memories, magnetic storage media such as a magnetic disks and magnetic tapes, hard drives, or optically readable digital data storage media.
Although specific embodiments are described herein, the scope of the disclosure is not limited to those specific embodiments. The scope of the disclosure is defined by the following claims and any equivalents thereof.
