Arc-shaped preform weaving device and design method thereof

Abstract

The invention relates to the technical field of spinning, in particular to an arc-shaped preform weaving device and a design method thereof. The device comprises a curved profiled web mounted on the surface of a roller for winding warp and weft; the outer surface of the bent special-shaped web plate comprises a semi-cylindrical surface part and a semi-conical surface part connected with one end of the semi-cylindrical surface part in the axial direction, the generatrix of the semi-cylindrical surface part is parallel to the generatrix of the roller, and the curvature radius of an arc at the larger end of the semi-conical surface part is the same as that of an arc at one end of the semi-cylindrical surface part; the curvature radius of the smaller end of the semi-conical surface part is the same as the radius of the roller, so that the smaller end of the semi-conical surface part is attached to the surface of the roller, the side surfaces are located on the two sides of the outer surface, and the side edges of the outer surface and the edges, not connected with the outer surface, of the inner surface are connected through the side surfaces. According to the scheme, the device capable of achieving high-quality weaving forming of the straight section and arc section integrated prefabricated body can be provided.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and in particular to an arc-shaped prefabricated weaving device and its design method. Background Technology

[0002] Three-dimensional woven preforms, with their lightweight, high strength, and excellent mechanical properties, have become a key reinforcing structure for high-performance composite materials and are widely used in aerospace, defense, and transportation industries. However, existing technologies still face significant challenges in manufacturing preforms with complex curved surfaces.

[0003] Currently, there are three main methods for forming curved preforms: 1. Planar fabric splicing process, which achieves curved surface forming by sewing together multiple pieces of two-dimensional fabric. However, this method suffers from discontinuous yarns at the seams, leading to a decrease in the interfacial properties of the composite material, and the high proportion of manual operation affects production efficiency. 2. Controlled fiber fracture technology, which achieves curved surface forming by applying overload tension to local fibers. However, this inevitably damages the fiber network, thereby weakening the overall mechanical properties of the material. Precisely controlling the path change of carbon fiber preforms in the curved region to ensure the uniformity and continuity of fiber volume fraction remains a technical challenge in the weaving process of three-dimensional preforms. Therefore, there is an urgent need for a device capable of achieving high-quality weaving and forming of integrated preforms with both straight and curved sections. Summary of the Invention

[0004] The present invention provides a weaving device and design method for an arc-shaped preform, which can provide a device that can achieve high-quality weaving and forming of such an integrated preform with straight and arc-shaped sections.

[0005] In a first aspect, embodiments of the present invention provide an arc-shaped prefabricated weaving device, including a curved profiled web mounted on the surface of rollers used for winding warp and weft yarns; The curved irregular web includes an inner surface, an outer surface, and side surfaces. The inner surface is curved, and its curvature matches that of the roller, so that the curved irregular web fits snugly against the roller surface. The outer surface includes a semi-cylindrical portion and a semi-conical portion connected to one end of the semi-cylindrical portion along the axial direction. The generatrix of the semi-cylindrical portion is parallel to the generatrix of the roller. The radius of curvature of the arc at the larger end of the semi-conical portion is the same as the radius of curvature of the arc at one end of the semi-cylindrical portion. The radius of curvature of the smaller end of the semi-conical portion is the same as the radius of curvature of the roller, so that the smaller end of the semi-conical portion fits snugly against the roller surface. The side surfaces are located on both sides of the outer surface, and the side surfaces connect the side edges of the outer surface to the edges of the inner surface that are not connected to the outer surface.

[0006] In one possible design, a drive mechanism for rotating the roller and a transmission gear set are also included. The drive mechanism includes a servo motor and a reducer, and the transmission gear set connects the drive mechanism and the roller shaft.

[0007] In one possible design, multiple sets of yarn-fixing holes and threaded holes for fixing the curved web are arranged side by side above the roller.

[0008] In one possible design, a pressure bar mechanism is also included, comprising a pressure bar and a bar seat, the bar seat being fixed to the roller, and the pressure bar being fixed to the bar seat by an adjusting bolt, the pressure bar being located upstream of the bending irregular web in the direction of rotation.

[0009] In one possible design, a control system is also included for controlling the servo motor.

[0010] In one possible design, the preformed warp yarns are fixed to the rollers through threading holes.

[0011] In one possible design, the angle α between the generatrix of the semi-conical portion and the axis of the roller is less than 50°.

[0012] Secondly, embodiments of the present invention provide a design method for an arc-shaped prefabricated body weaving device. Based on any of the above-mentioned devices, the design method includes: Obtain the target radius of curvature and the thickness of the preform in the curved section; The first radius of curvature of the smaller end of the semi-conical portion is determined based on the radius of the roller; The wrap angle of the curved web on the roller is determined based on the arc length of the curved section of the preform. The second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the preform thickness, the first radius of curvature, and the wrap angle. The curved irregular web is obtained by processing according to the first radius of curvature and the second radius of curvature.

[0013] In one possible design, the second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the preform thickness, the first radius of curvature, and the wrap angle, using the following formula: Wherein, ρ is the target radius of curvature. The difference in radii at both ends of the semi-conical portion causes a gradient in the warp yarn consumption of the prefabricated fabric during the winding process. ω is the reference length, ω is the thickness of the preform, θ is the wrap angle, the first radius of curvature is r1, and the second radius of curvature is r2.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: At least one curved irregular web fixed on the outer surface of the roller. The curved irregular web is divided into two parts: a semi-cylindrical part and a semi-conical part. The generatrix of the semi-cylindrical part is parallel to the roller axis, and the radius of curvature is always r2. The semi-cylindrical part is used to form the outer wing plate of the preform. The generatrix of the semi-conical part forms an angle α with the roller axis. Its radius smoothly transitions from one end r2 (large end radius of curvature) connecting the semi-cylindrical part to the other end r1 (small end radius of curvature). The semi-conical part is used to form the arc-shaped web of the preform. When the preform passes through the irregular web, the radius difference between the two ends of the semi-conical part causes the warp yarns of the preform fabric to have a gradient consumption during the winding process. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 The prefabricated structure to which this invention applies; Figure 2 This is a front view of the arc-shaped preform forming device; Figure 3 Axial view of the arc-shaped preform forming device; Figure 4 A schematic diagram of the irregular web structure of the arc-shaped preform forming device; Figure 5 Front and side views of the irregular web of the arc-shaped precast forming device; Figure 6 Standardized irregular web plate series for arc preform forming device; Figure 7 A schematic diagram of the pressure bar mechanism of the arc-shaped preform forming device; Figure 8 A schematic diagram of the yarn direction during the weaving of the preform for the arc-shaped preform forming device.

[0017] In the picture: 1. Precast web; 2. Flange; 3. Drive mechanism; 4. Transmission gear set; 5. Curved irregular web; 6. Roller; 7. Pressure bar mechanism; 8. Frame; 9. Bolt; 10. Rod seat; 11. Pressure bar; 12. Adjusting screw. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0020] In this specification, it should be understood that the directional terms such as "upper" and "lower" used in the description of the embodiments of the present invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should also be understood that when it is mentioned that one element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0021] This invention provides an arc-shaped prefabricated weaving device, including a curved irregular web 5 mounted on the surface of a roller 6 used for winding warp and weft yarns; The curved irregular web 5 includes an inner surface, an outer surface, and a side surface. The inner surface is curved, and its curvature is consistent with that of the roller 6, so that the curved irregular web 5 is fitted onto the surface of the roller 6. The outer surface includes a semi-cylindrical portion and a semi-conical portion connected to one end of the semi-cylindrical portion along the axial direction. The generatrix of the semi-cylindrical portion is parallel to the generatrix of the roller 6. The radius of curvature of the arc at the larger end of the semi-conical portion is the same as the radius of curvature of the arc at one end of the semi-cylindrical portion. The radius of curvature of the smaller end of the semi-conical portion is the same as the radius of curvature of the roller 6, so that the smaller end of the semi-conical portion is fitted onto the surface of the roller 6. The side surfaces are located on both sides of the outer surface and connect the side edges of the outer surface and the edges of the inner surface that are not connected to the outer surface.

[0022] Roller 6 is fixed to frame 8. At least one curved irregular web 5 is fixed to the outer surface of roller 6. The outer surface of the curved irregular web 5 is divided into a semi-cylindrical part and a semi-conical part. The generatrix of the semi-cylindrical part is parallel to the axis of roller 6, and the radius of curvature is always r2. The semi-cylindrical part is used to form the outer wing plate of the preform. The generatrix of the semi-conical part forms an angle α with the axis of roller 6. Its radius smoothly transitions from one end r2 (large end radius of curvature) connecting to the semi-cylindrical part to the other end r1 (small end radius of curvature). The semi-conical part is used to form the arc-shaped web of the preform. When the preform passes through the irregular web, the difference in the radius of curvature at both ends of the semi-conical part causes a gradient in the consumption of warp yarns during the winding process of the preform fabric.

[0023] Specifically, the prefabricated body comprises a straight section and a curved section, including at least one curved prefabricated body web 1 and a flange 2, with a cross-section in the shape of a "T", "J" or "I". The web includes weft yarns along the warp direction and warp yarns in the circumferential direction along the axis of rotation, while the flange includes warp yarns in the circumferential direction and weft yarns in the axial direction along the axis of rotation. By bending the irregularly shaped web 5, the warp yarn consumption on one side of the prefabricated body is made different during the winding process, so that the warp yarn length change along the weft direction in the curved part of the prefabricated body adapts to the arc length of the bend. After the prefabricated body is woven, it can achieve natural bending. This device adopts a modular design to realize the integrated design of the prefabricated body including the straight section and the curved section, which greatly reduces the weaving cost of complex-shaped prefabricated bodies and improves manufacturing efficiency.

[0024] In some embodiments of the present invention, a drive mechanism 3 and a transmission gear set 4 for rotating the roller 6 are also included. The drive mechanism 3 includes a servo motor and a reducer, and the transmission gear set 4 connects the drive mechanism 3 and the rotating shaft of the roller 6.

[0025] In some embodiments of the present invention, multiple sets of yarn-fixing holes and threaded holes for fixing the curved irregular web plate 5 are arranged side by side above the roller 6.

[0026] In this embodiment, roller 6 is a circular roller of uniform diameter, serving as a carrier for winding and preform forming. Multiple sets of yarn-binding holes and threaded holes are arranged side-by-side on its top to fix the yarn and the curved irregular web 5. The curved irregular web 5 is fixed to roller 6 via its threaded holes and bolts 9.

[0027] In some embodiments of the present invention, a pressure rod 7 is also included. The pressure rod 7 includes a pressure rod 11 and a rod seat 10. The rod seat 10 is fixed on the roller 6, and the pressure rod 11 is fixed on the rod seat 10 by adjusting bolts 9. The pressure rod 11 is located upstream of the rotation direction of the curved irregular web 5.

[0028] The height of the pressure rod 7 can be adjusted by adjusting the screw 12, or by hydraulic or pneumatic means, to accommodate preforms of different thicknesses. The pressure rod 7 is fixed to the roller 6 and rotates with it. It consists of a pressure rod seat 10 and the pressure rod 11, and is installed at the front end of the curved web 5 in the inlet direction. It guides the yarn into the curved area at the correct angle and position before the preform fabric is wound onto the curved web 5, and uses pressure to suppress radial movement and stacking tendencies of the yarn. The pressure rod 11 is a rigid rod with a smooth surface, and the adjusting screw 12 is a fine-pitch screw with a locking nut. By rotating the adjusting screw 12, the gap between the pressure rod 11 and the surface of the roller 6 can be precisely controlled, thus adapting to preforms of different layers and thicknesses.

[0029] In some embodiments of the present invention, a control system is also included, which is used to control the servo motor.

[0030] In some embodiments of the present invention, the preform warp yarns are fixed to the roller 6 through threading holes. The preform warp yarns are fixed to the roller 6 through threading holes, and the roller 6 rotates clockwise to wind the preform fabric onto the roller 6.

[0031] In some embodiments of the present invention, the angle α between the generatrix of the semi-conical portion and the axis of roller 6 is less than 50°.

[0032] Secondly, embodiments of the present invention provide a design method for an arc-shaped preform weaving device. Based on any of the above-mentioned devices, the design method includes: Obtain the target radius of curvature and the thickness of the preform in the curved section; The first radius of curvature of the smaller end of the semi-conical portion is determined based on the radius of roller 6; The wrap angle of the curved web 5 on the roller 6 is determined based on the arc length of the curved section of the precast body. The second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the thickness of the preform, the first radius of curvature, and the wrap angle. The curved irregular web 5 is obtained by processing according to the first radius of curvature and the second radius of curvature.

[0033] After obtaining the curved irregular web 5, the following steps are also included: The working surface of the curved profiled web 5 requires a high-gloss finish (such as polishing, chrome plating, or spraying with a wear-resistant coating). All edges, especially the joints with the roller 6, must be machined into smooth, gently sloping transitions to prevent fiber damage. The manufactured curved profiled web 5 is precisely fixed to the preset axial position of the roller 6 using bolts 9. During installation, it must be ensured that the generatrix of its semi-cylindrical portion is parallel to the axis of the roller 6.

[0034] Fix the base of the pressure bar 7 onto the roller 6, and ensure that it is located at the front end of the yarn inlet of the curved web 5 along the direction of rotation.

[0035] By rotating the adjusting screw 12 of the pressure bar 7, the gap between the pressure bar 11 and the surface of the roller 6 is precisely set. This gap value should be less than or equal to the design thickness of the preform to provide appropriate pre-compression force, ensuring that the yarn is initially bundled and positioned before entering the bending area.

[0036] Yarn guiding: The warp bundle from the yarn frame is guided through the yarn guiding device and tension control system, and evenly guided to the front of roller 6, so that its width covers the entire working surface of the curved irregular web 5. The yarn end is temporarily fixed to the yarn fastening hole of roller 6.

[0037] Set equipment operating parameters: Based on the process parameters of the woven preform, set the servo motor winding speed and target number of winding turns (or length) in the control system. Ensure that the set tension and speed can guarantee stable yarn tension and no slippage during the winding process.

[0038] Start winding: Start the drive system, the servo motor runs according to preset parameters, and drives the roller 6 to rotate at a constant speed in the set direction.

[0039] Synchronous compaction and guidance: The rotating roller 6 drives the pressure bar 7 to move together. The yarn is compressed and guided under the constraint of the pressure bar 11, and then immediately wound onto the surface of the curved profiled web 5.

[0040] Gradient consumption and natural bending: In areas not covered by the curved web 5, all warp yarns are consumed at a uniform rate, forming a straight prefabricated segment.

[0041] In the semi-conical portion of the curved web 5, due to the gradual change in radius from r1 to r2, the outer yarns are consumed at a faster rate than the inner yarns, resulting in a gradient difference in warp consumption ∆L. This length difference is automatically and uniformly converted into a bending moment, forcing the entire fabric strip to accurately conform to the conical surface of the curved web, so that the preform naturally takes shape into a curved preform segment with a predetermined radius of curvature ρ after weaving.

[0042] In the semi-cylindrical portion of the curved irregular web 5, during the actual weaving process, the semi-cylindrical portion of the preform consists of two parts. One part is wound around the semi-cylindrical portion of the irregular web with a winding radius of r2. This part, when unfolded, becomes the outer wing plate of the preform. The other part is wound around the roller 6. This part, when unfolded, becomes the inner wing plate of the preform.

[0043] Completion and unloading: The equipment will automatically stop after the preset number of windings is reached. Cut the yarn and release the pressure of the pressure bar 7 to remove the formed integrated preform from the device.

[0044] Production conversion: If it is necessary to produce preforms with different curvatures, simply replace them with another curved irregular web plate 5 module that has been recalculated and designed according to the target curvature, and readjust the gap of the pressure bar 11 to achieve rapid production conversion.

[0045] Through the above steps, this invention achieves precise, controllable, and efficient production of preforms with curved sections. The method's versatility lies in its core reliance on physical formulas and modular mechanical structures, rather than specific products, thus possessing broad applicability.

[0046] In some embodiments of the present invention, the second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the preform thickness, the first radius of curvature, and the wrap angle, and is achieved by the following formula: Where ρ is the target radius of curvature. The difference in radius between the two ends of the semi-conical portion causes a gradient in the warp yarn consumption during the winding process of the prefabricated fabric. ω is the reference length, θ is the preform thickness, θ is the wrap angle, the first radius of curvature is r1, and the second radius of curvature is r2.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A weaving device for an arc-shaped prefabricated body, characterized in that, Includes a curved web (5) mounted on the surface of the rollers (6) used for winding warp and weft yarns; The curved irregular web (5) includes an inner surface, an outer surface, and a side surface. The inner surface is curved and its curvature is consistent with that of the roller (6) so that the curved irregular web (5) is fitted onto the surface of the roller (6). The outer surface includes a semi-cylindrical portion and a semi-conical portion connected to one end of the semi-cylindrical portion along the axial direction. The generatrix of the semi-cylindrical portion is parallel to the generatrix of the roller (6). The radius of curvature of the arc at the larger end of the semi-conical portion is the same as the radius of curvature of the arc at one end of the semi-cylindrical portion. The radius of curvature of the smaller end of the semi-conical portion is the same as the radius of curvature of the roller (6) so that the smaller end of the semi-conical portion is fitted onto the surface of the roller (6). The side surface is located on both sides of the outer surface and connects the side edge of the outer surface to the edge of the inner surface that is not connected to the outer surface.

2. The apparatus according to claim 1, characterized in that, It also includes a drive mechanism (3) and a transmission gear set (4) for rotating the roller (6), the drive mechanism (3) including a servo motor and a reducer, and the transmission gear set (4) connecting the drive mechanism (3) and the roller (6) shaft.

3. The apparatus according to claim 1, characterized in that, Multiple sets of yarn-fixing holes and threaded holes for fixing the curved web (5) are arranged side by side above the roller (6).

4. The apparatus according to claim 1, characterized in that, It also includes a pressure rod (7), which includes a pressure rod (11) and a rod seat (10). The rod seat (10) is fixed on the roller (6), and the pressure rod (11) is fixed on the rod seat (10) by an adjusting bolt (9). The pressure rod (11) is located upstream of the rotation direction of the curved irregular web (5).

5. The apparatus according to claim 2, characterized in that, It also includes a control system for controlling the servo motor.

6. The apparatus according to claim 1, characterized in that, The preformed warp yarns are fixed on the roller (6) through the yarn threading holes.

7. The apparatus according to claim 1, characterized in that, The angle α between the generatrix of the semi-conical portion and the axis of the roller (6) is less than 50°.

8. A design method for an arc-shaped prefabricated body weaving device, characterized in that, Based on the apparatus according to any one of claims 1-7, the design method includes: Obtain the target radius of curvature and the thickness of the preform in the curved section; The first radius of curvature of the smaller end of the semi-conical portion is determined based on the radius of the roller (6); The wrap angle of the curved web (5) on the roller (6) is determined according to the arc length of the curved section of the preform; The second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the preform thickness, the first radius of curvature, and the wrap angle. The curved irregular web (5) is obtained by processing according to the first radius of curvature and the second radius of curvature.

9. The design method according to claim 8, characterized in that, The second radius of curvature of the semi-cylindrical portion is determined based on the target radius of curvature, the preform thickness, the first radius of curvature, and the wrap angle, using the following formula: Wherein, ρ is the target radius of curvature. The difference in radii at both ends of the semi-conical portion causes a gradient in the warp yarn consumption of the prefabricated fabric during the winding process. ω is the reference length, ω is the thickness of the preform, θ is the wrap angle, the first radius of curvature is r1, and the second radius of curvature is r2.

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