Patent Application
20210363674
Exemplary embodiments of the present disclosure pertain to the art of robotic weaving of structures having varying contours.
Woven structures are known. Woven structures are made of multiple picks along the formation direction. In some traditional weaving techniques, the term “pick” describes one fill fiber that has been deposited and encapsulated by the entire array of warp fibers one row at a time. The term “pick” may apply to encapsulation of the fill fiber by one adjacent pair of warp fibers at a time.
Many components, such as ceramic matrix composite (CMC) or organic matrix composite (OMC) components used in a jet engine, use woven structures as preforms. The woven structure strengthens the component. During manufacturing of such components, the woven structure is placed in a mold as a precursor. A material is then injected into the remaining areas of the mold or deposited on the woven structure. The material surrounds the woven structure within the mold. If the mold has varying contours, manipulating woven assemblies, which are relatively planar, into a shape suitable for placing into the mold is difficult. Methods for forming three dimensional woven structures are desired.
Disclosed is a weaving assembly including a rotatable base, a base positional controller, a weave control grid, a warp fiber support, warp fiber arms, a warp fiber arm positional controller and a fill fiber wand.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the weave control grid is located on the rotatable base.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the rotatable base rotates relative to the fill fiber wand and warp fiber arms.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support rotates with the base.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support rotates independently of the base.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support includes movable segments.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the movable segments have differing shapes.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support includes notches.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the weaving assembly includes more than one warp fiber support. The warp fiber supports can be moved independently.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the weaving assembly includes a movable guide. The movable guide may include segments and the segments may be moved independently. Also disclosed is a weaving method including placing a first section of a fill fiber between warp fibers, forming a pick, rotating a base to reposition the warp fibers, and placing a second section of the fill fiber between the warp fibers to form a woven structure, wherein at least a portion of the warp fibers are introduced to the woven structure using a weave control grid and at least a portion of the warp fibers are in contact with at least a portion of a warp fiber support.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support rotates with the base.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support includes segments. The segments may be moved independently.
In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the warp fiber support has a contour in contact with the warp fibers and the contour relates to a final shape of a woven structure.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed assembly and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
When weaving the woven structure 14, the wand 18 positions a fill fiber 30 between warp fibers 42. Controlled spacing of the warp fibers is important to consistent production of the woven structure. The fill fiber 30 extends from a spool 34 through a bore 38 in the wand 18. The wand 18, in this example, is a hollow tube. A fill fiber feed device may be included to meter the feed rate of the fill fiber with respect to the instantaneous relative velocity of the wand tip to the textile being created. The warp fibers 42 are manipulated by warp fiber arms 26.
The assembly 10 includes a positional controller 46 associated with the wand 18, a positional controller 50 associated with the warp fiber arms 26, and a positional controller 54 associated with the weaving apparatus 22. The positional controller 46 is able to move the wand 18 relative to the warp fiber arms 26 and the weaving apparatus 22. The positional controller 50 is able to move the warp fiber arms 26 relative to the wand 18 and the weaving apparatus 22. The positional controller 54 is able to move the weaving apparatus 22 relative to the wand 18 and the warp fiber arms 26. The positional controllers 46, 50, and 54 can be operated independently from each other or together.
Referring to
The base 20 in
While
The weaving apparatus 22 may optionally include a movable guide 70. Movable guide 70 is oriented at an angle greater than 90 degrees and less than or equal to 180 degrees relative to the base 20. Similar to the warp fiber support 60 movable guide 70 may have segments which enable the movable guide to change the shape in contact with the warp fibers as needed to support and locate the warp fibers. The movable guide 70 location may be managed by positional controller 54 or a separate positional controller. Also shown in
Component 80 may be held in place by component constraint 90 as shown in
The supports and movable guides (when present) can be made from many different materials. Supports may be made from a hard or hardenable material such as cast iron, or a metal substrate with a hardface applied, such as “Stellite”, to reduce wear caused by the fiber. Alternatively, the supports may have a slippery surface like a polytetrafluoroethylene coating or surfaces made from plastic, such as polyamide, to minimize friction or snagging of the individual filament within the fiber. Additionally, the supports, movable guides and/or overall system made be made from high-temperature materials such a graphite, silicon carbide, silicon nitride or an oxide material such as aluminum oxide.
The materials used for the supports may be different for each support and/or segment, based upon the dynamics of the fiber manipulation. Simple segments may be made from inexpensive steel or plastic. Supports which are used to change the fundamental direction and compaction of the fibers may be made from a material better suited to the loads and motions of the fibers.
Referring to
Exemplary fiber materials include glass, graphite, polyethylene, aramid, ceramic, boron and combinations thereof. One of the fill fibers 30 or warp fibers 42 may include hundreds or thousands of individual filaments. In some embodiments the fill fibers include 500 to 800 filaments. Fibers are also sometimes referred to as “tows”. The individual filaments may have diameters that range from 5 to 25 microns, although boron filaments may be up to 142 microns in diameter.
Each of the warp fiber arms may hold one or several of the warp fibers 42. After crossing the warp fibers 42 over the fill fiber 30, the warp fiber arms hand-off the warp fiber 42 to another of the warp fiber arms or places it in groove 40. The “hand-off” feature allows an open shed so that the warp fiber arms do not interfere with the wand 18. After the hand-off, the warp fiber arms are then crossed over another section of the fill fiber 30 to form another pick 58.
The warp fiber arms engage portions of the warp fibers 42. These portions may include end fittings. The warp fiber arms grab the end fittings holding the warp fibers 42. The end fittings may be placed in groove 40 to help maintain the position of the warp fibers 42 during weaving.
A person having skill in this art and the benefit of this disclosure would understand how to create picks by crossing warp fibers over a fill fiber, and how to hand-off a warp fiber from one warp fiber arm to another warp fiber arm.
When weaving, the wand 18 moves the fill fiber 30 past the warp fibers 42. The wand 18 moves the fill fiber 30 in a spiral to create built-up layers of picks 58 as the base rotates. The rim may move with the base or separately. The wand 18 may be long enough to reach down through the longest warp fibers 42 during the weaving.
Elements of the weaving apparatus 22 are moved as dictated by the design of the woven structure 14 to create the shape of the woven structure 14. Elements of the weaving apparatus 22 are thus capable of movement relative to the warp fiber arms 26.
For example, the base 20 rotates so that the pick formation point is at a position relative to the wand 18, and the fill fiber 30, and the warp fiber support is moved to provide support to the warp fibers as they are manipulated to form bends and curves. Segments in the warp fiber support facilitate the development of three-dimensional shapes.
The path and manipulations of the weaving apparatus 22 with the positional controller 54, the number of warp fibers 42 engaged by the warp fiber arms 26 when forming each pick, and the sequence of warp fiber arm movements may be designed and pre-planned in a software model to produce the woven structure 14 having the desired contours. A stable shape is obtained by the interplay of fiber forces and friction within the textile unit cells throughout the component.
The software model may utilize as inputs: a CAD definition of the surfaces of a desired component incorporating the woven structure; a definition of the initial warp fibers' lengths, locations, and orientations; and a definition of a textile repeating unit cell (or pick). The software calculates motions of the wand 18, weaving apparatus 22, and warp fiber arms 26 necessary to achieve desired contours in the woven structure 14, without colliding into each other. The software model is then used as input for the positional controllers 46, 50, 54, and control of the fill fiber wand.
Referring to
When weaving is complete the woven structure may be removed from the assembly and may be subjected to further processing such as consolidation or matrix deposition. In some embodiments the woven structure may be separated from a portion of the weaving assembly while leaving portions of the weaving assembly in contact with the woven structure during subsequent processing. When portions of the weaving assembly are left in contact with the woven structure during further processing the materials used to form these portions are chosen to withstand the processing conditions.
Features of the disclosed method and assembly include a relatively precise and repeatable mechanized process that is conducive to high volume production of complex shape components such as turbine engine components with precise and repeatable introduction of warp fibers as the woven structure evolves. Locating the warp fibers in close proximity to the desired position for incorporation into weaving and with controlled spacing results in a more consistent and precise woven structure with better reproducibility of physical characteristics between woven structures.
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
