Fiber-reinforced composite core manufacturing equipment

Abstract

The present invention relates to the technical field of composite cores, and in particular to a manufacturing device for a fiber-reinforced composite core, comprising a creel, a three-dimensional preform forming device, a pretreatment device, a shaping device, and a traction machine arranged in sequence, wherein a plurality of fiber bundles are placed on the creel; the three-dimensional preform forming device regularly and alternately interlocks the plurality of fiber bundles to form a three-dimensional preform, which is a three-dimensional fabric having an internal structure and an outer contour interwoven into one, and is a non-layered integral structure; the pretreatment device pretreats the three-dimensional preform; the shaping device impregnates the three-dimensional preform with resin and pultrudes it to form a fiber-reinforced composite core; the traction machine provides a traction force from the creel to the traction machine, and the traction force simultaneously pulls the fiber bundles, the three-dimensional preform, and the fiber-reinforced composite core. Combining the three-dimensional preform with the pultrusion process fully utilizes the continuity and low cost characteristics of the pultrusion process and the excellent comprehensive performance characteristics of the three-dimensional preform.

Description

Technical Field

[0001] The present invention relates to the technical field of composite cores, and in particular to a manufacturing device for a fiber-reinforced composite core. Background Art

[0002] High-performance fibers, with their excellent mechanical properties, are combined with resins to create composite cores, replacing steel strands as load-bearing structures and are widely used in transmission cables. Carbon fibers, with their light weight, high corrosion resistance, non-magnetic properties, high thermal conductivity, extremely low thermal expansion coefficient, high tensile strength, and high tensile elasticity, are the primary applications.

[0003] Conventional composite cores are obtained by pultruding high-performance fibers into bundles along the axial direction (or adding winding and tube-sheath braiding processes) and then impregnating them with resin to obtain a composite core with a certain cross-sectional shape.

[0004] Among them, fiber-reinforced composite cores produced using a unidirectional fiber pultrusion process have fiber filaments arranged parallel only along the axial direction. While they exhibit excellent axial tensile strength, they lack circumferential fiber reinforcement, with the parallel fiber filaments bonded solely by resin. Consequently, the resulting composite cores exhibit insufficient radial compression and axial bending resistance. In particular, when the composite cores are subjected to radial compression, they are prone to diametrical splitting. Under frequent external forces, cracks can rapidly propagate along the poorly bonded interface between the fiber filaments and the resin, leading to composite core failure.

[0005] The part prepared by the unidirectional fiber pultrusion process is used as the shaft core, and the fiber winding process is added along the circumferential direction on the outside of the shaft core to obtain a fiber-reinforced composite core with a surface spiral structure. The wound fibers bundle the shaft core fibers tightly, restricting the movement of the shaft core fibers and improving the radial compression resistance and axial bending resistance. However, the wound fibers are only spirally stacked along a certain circumferential direction, and the contact area between the fiber spiral rings is small. They are only fixed by resin bonding. The torsional resistance and fatigue resistance of the obtained composite core are still poor.

[0006] The part prepared by the unidirectional fiber pultrusion process is used as the shaft core, and the fiber tubular weaving process is added along the circumferential direction on the outside of the shaft core to obtain a fiber-reinforced composite core with a braided tube sleeve surface layer. The woven fibers form a tube sleeve outside the shaft core fibers, and each fiber bundle woven into a tube is regularly cross-interlocked at a certain angle to the axis. This structure not only enhances the radial compression resistance and circumferential stiffness of the composite core, but also improves its torsional resistance and partial axial tensile performance, which is an upgrade of the winding process.

[0007] The winding and braiding processes improve the circumferential performance of a portion of the unidirectional fiber pultruded composite core to varying degrees. However, when combined with the unidirectional fiber pultrusion process, both processes form a "skin-core structure," where the winding and braiding layers are both skin layers, and the unidirectional fiber pultruded portion is the axial core. In the production of such components, when the winding or braiding rate is mismatched with the pultrusion rate, delamination is likely to occur, seriously affecting product performance. In addition, the skin layer cannot effectively control the propagation of cracks within the axial core. Once the axial core is damaged, the composite core still tends to fail rapidly. Therefore, composite cores with a "skin-core structure" exhibit poor fatigue resistance and impact resistance. The poor performance of the overall mechanical properties limits the application of composite cores, making it difficult to meet more stringent usage requirements. Summary of the Invention

[0008] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a manufacturing device for a fiber-reinforced composite core, which can obtain a fiber-reinforced composite core with excellent comprehensive mechanical properties.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions: a manufacturing device for a fiber-reinforced composite core, comprising a creel, a three-dimensional preform forming device, a pretreatment device, a shaping device and a traction machine arranged in sequence, wherein a plurality of fiber bundles are placed on the creel; the three-dimensional preform forming device regularly and alternately interlocks the plurality of fiber bundles to form a three-dimensional preform, wherein the three-dimensional preform is a three-dimensional fabric, and the three-dimensional preform has an internal structure and an outer contour interwoven into one, and the three-dimensional preform is a non-layered integral structure; the pretreatment device pretreats the three-dimensional preform; the shaping device resin-impregnates and pultrudes the pretreated three-dimensional preform to form a fiber-reinforced composite core; the traction machine provides a traction force from the creel to the traction machine, and the traction force simultaneously pulls the fiber bundles, the three-dimensional preform and the fiber-reinforced composite core.

[0010] Preferably, the three-dimensional preform forming device comprises a three-dimensional textile machine.

[0011] Preferably, the pretreatment device includes a preforming device, a preheating device and a compression device arranged in sequence along the traction direction of the traction force, the preforming device compresses the three-dimensional preform prepared by the three-dimensional preform forming device once, the preheating device preheats the three-dimensional preform after the once compression, and the compression device compresses the preheated three-dimensional preform twice.

[0012] Preferably, the compression direction in which the preforming device performs the primary compression on the three-dimensional preform and the compression direction in which the compression device performs the secondary compression on the three-dimensional preform are perpendicular to each other.

[0013] Preferably, the preforming device includes two preforming opening and closing parts that are relatively arranged to be separated or connected along the compression direction of a single compression, and a preforming cavity that passes through along the traction direction of the traction force is formed between the two connected preforming opening and closing parts. The preforming cavity includes a preforming straight section with a diameter smaller than the outer contour diameter of the three-dimensional preform and a preforming trumpet section with a gradually increasing diameter extending from both ends of the preforming straight section.

[0014] Preferably, the cavity wall of the pre-forming cavity is provided with a coating.

[0015] Preferably, the compression device includes two compression opening and closing parts that are relatively arranged to be separated or connected along the compression direction of the secondary compression, and a compression chamber that passes through along the traction direction of the traction force is formed between the two connected compression opening and closing parts. The compression chamber includes a compression straight section with a diameter not greater than the outer contour diameter of the three-dimensional preform after the first compression and a compression bell-mouth section with a gradually increasing diameter extending from both ends of the compression straight section.

[0016] Preferably, a first resin injection port is provided on each of the two compression opening and closing parts. The two first resin injection ports are respectively located at the two ends of the compression straight section and are arranged in opposite positions along the compression direction of the secondary compression. The two first resin injection ports are used to pressure-inject resin into the compression cavity.

[0017] Preferably, the shaping device includes a shaping mold, a shaping cavity is formed inside the shaping mold and passes through along the traction direction of the traction force, the shaping mold is provided with a second resin injection port connected to the shaping cavity and a high-temperature curing zone for heating the inside of the shaping cavity, the second resin injection port is used to pressure-inject resin into the shaping cavity, and the high-temperature curing zone is located on the side of the second resin injection port close to the traction machine.

[0018] Preferably, a collecting system for collecting the fiber-reinforced composite core is provided between the shaping device and the traction machine.

[0019] Compared with the prior art, the present invention has significant improvements:

[0020] The manufacturing equipment for the fiber-reinforced composite core of the present invention combines three-dimensional preform molding with a composite core pultrusion molding process, giving full play to the continuity, low cost, high efficiency, and high-quality control characteristics of the composite core pultrusion molding process, and the three-dimensional preform can effectively improve the comprehensive performance of interlayer shear resistance, impact resistance, fatigue resistance, etc., as well as the characteristic of being able to be integrally formed to a net size. The three-dimensional preform is a complete, non-layered, integral structure composed of fiber bundles without a skin-core structure, which can be integrally formed to a net size and has the distribution characteristics of multi-axial fiber reinforcement. This makes the fiber-reinforced composite core have more outstanding comprehensive properties such as tensile strength, compression resistance, bending resistance, and torsion resistance, while also having dynamic fatigue and impact resistance, excellent comprehensive mechanical properties, and the advantages of high degree of integral structural molding, outstanding contour design capability, strong multi-axial performance designability, strong strength, toughness, and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a manufacturing device for a fiber-reinforced composite core according to an embodiment of the present invention.

[0022] Figure 2 It is a schematic structural diagram of a fiber-reinforced composite core produced by the manufacturing equipment of the fiber-reinforced composite core according to an embodiment of the present invention.

[0023] Figure 3 yes Figure 2 A schematic diagram of the local structure of a three-dimensional preform in a fiber-reinforced composite core is shown.

[0024] Figure 4 yes Figure 2 A schematic diagram of the side structure of a three-dimensional preform in a fiber-reinforced composite core is shown.

[0025] Figure 5 It is a structural schematic diagram of a three-dimensional textile machine in the manufacturing equipment of the fiber-reinforced composite core according to an embodiment of the present invention.

[0026] Figure 6 It is a structural schematic diagram of a fiber bundle preforming and bundling device in a manufacturing device for a fiber-reinforced composite core according to an embodiment of the present invention.

[0027] Figure 7 yes Figure 2 A schematic diagram of the cross-sectional structure of a three-dimensional preform in a fiber-reinforced composite core is shown.

[0028] Figure 8 yes Figure 2 Schematic diagram of the cross-sectional structure of the fiber-reinforced composite core is shown.

[0029] Figure 9 It is a structural schematic diagram of a preforming device in the manufacturing equipment of the fiber reinforced composite core according to an embodiment of the present invention.

[0030] Figure 10 It is a structural schematic diagram of a compression device in the manufacturing equipment of the fiber reinforced composite core according to an embodiment of the present invention.

[0031] Figure 11 It is a structural schematic diagram of a shaping die in the manufacturing equipment of the fiber reinforced composite core according to an embodiment of the present invention.

[0032] The description of the accompanying drawings is as follows:

[0033] 100 3D prefabs

[0034] 101 Warp

[0035] 102, 102a Weft yarn

[0036] 200 resin

[0037] 201 resin surface layer

[0038] 202 resin filling layer

[0039] 300 Three-dimensional Textile Machine

[0040] 301 steel reed

[0041] 302 cloth area

[0042] 400 Fiber bundle preforming and bundling device

[0043] 1 Creel

[0044] 2 Three-dimensional preform forming device

[0045] 3 Preforming device

[0046] 31 Preformed opening and closing part

[0047] 32 Preformed Cavity

[0048] 32a Preformed straight section

[0049] 32b Preformed bell section

[0050] 4 Preheating device

[0051] 5 Compression device

[0052] 51 Compression opening and closing part

[0053] 52 Compression chamber

[0054] 52a Compressed straight section

[0055] 52b Compression bell section

[0056] 53 First resin injection port

[0057] 6. Molding device

[0058] 61 Molding mold

[0059] 62 molding cavity

[0060] 63 Second resin injection port

[0061] 64 Mixing head

[0062] 7 Tractor DETAILED DESCRIPTION

[0063] The following is a further detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, and are not intended to limit the present invention.

[0064] In the description of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0066] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0067] To compensate for the circumferential performance deficiencies of unidirectional fiber pultruded composite cores, existing technologies such as winding and braiding are used to add winding / braided layers to the outer circumference of the axial core produced using the unidirectional fiber pultrusion process. If adding one layer still fails to meet the requirements, adding multiple layers is considered. However, regardless of the number of layers added, the resulting structure is a skin-core structure. Separation at the skin-core interface cannot be avoided when the composite core is damaged. Furthermore, the skin layer cannot effectively inhibit the propagation of crack damage within the core layer, resulting in rapid failure of the composite core and poor overall mechanical performance.

[0068] In order to overcome the defects of the skin-core structure, the present invention proposes a fiber-reinforced composite core with an integral structure. The fibers in the fiber-reinforced composite core constitute a complete, non-layered, integral structure without a skin-core structure. The fiber-reinforced composite core with this integral structure has more outstanding comprehensive properties such as tensile strength, compression strength, bending strength and torsional strength, and can have both dynamic fatigue and impact resistance, and therefore has more excellent comprehensive mechanical properties.

[0069] In composite materials other than composite cores, research has used three-dimensional preforms with monolithic structures as composite reinforcements. However, these composite materials are manufactured in a segmented manner, where a specific number of products are produced in one mold, and then repeated in multiple batches. This results in high manufacturing costs and low production efficiency. Pultrusion of composite cores is one of the few processes in the composites field that allows for continuous production, delivers outstanding mechanical properties along the pultrusion direction, and offers highly consistent quality, making it ideally suited to the low-cost, high-quality demands of industrial production. However, in existing research, researchers on composite core pultrusion processes are overly concerned with improving the performance of composite cores in a single direction, while researchers in other composite material process directions are overly concerned with optimizing the manufacturing cost and production efficiency of the segmented and batch preparation method of three-dimensional preforms. In addition, because the existing composite cores use winding and braiding processes to form winding layers and braided layers as reinforcements, their molding mechanism is relatively simple and the structure is not complicated. It is easier to control equipment, manufacturing quality, and especially the degree of resin impregnation than three-dimensional preforms. Therefore, existing technology for composite core research still focuses on improving the performance of the skin-core structure, without considering using three-dimensional preforms in the preparation of composite cores to replace the skin-core structure to improve the comprehensive mechanical properties of the composite core. This is a technical bias in the technical field of composite core preparation.

[0070] The present invention overcomes the above-mentioned technical prejudices and combines the three-dimensional preform molding with the composite core pultrusion molding process to obtain a fiber-reinforced composite core with an integral structure. The three-dimensional preform has the characteristics of strong designability, outstanding comprehensive performance (especially in terms of anti-delamination, impact resistance, fatigue resistance, etc.), high added value, and high manufacturing cost (mainly due to the large waste during segmented manufacturing). The continuous preparation of the composite core pultrusion molding process accurately offsets the problem of high manufacturing cost of the three-dimensional preform. In this way, a composite core with better comprehensive mechanical properties can be obtained. Moreover, since the molding of the three-dimensional preform is combined with the composite core pultrusion molding process to form a continuous preparation process, the manufacturing cost and production efficiency can be effectively and reasonably controlled, giving full play to the continuity, low cost, high efficiency, and high-quality control characteristics of the composite core pultrusion molding process and the three-dimensional preform can effectively improve the comprehensive performance of interlayer shear resistance, impact resistance, fatigue resistance, etc. and the characteristics of integrated net size molding.

[0071] Furthermore, existing composite core resin infiltration methods mostly use slotted resin baths. The degree of resin infiltration is significantly affected by resin fluidity and infiltration time. When combining three-dimensional preform molding with composite core pultrusion, using a slotted resin bath makes it difficult for the resin to penetrate the interior of the three-dimensional preform due to its complex internal structure. Incomplete infiltration of the three-dimensional preform creates a large number of pores within the preform, seriously affecting the performance of the composite core. To address this issue of resin infiltration within the three-dimensional preform, the present invention proposes the use of resin injection in the composite core pultrusion process to infiltrate the three-dimensional preform. Resin injection infiltration technology originates from the field of plastic extrusion technology. Liquid resin is pressurized and injected into a mold cavity of target size containing fibers using a separate machine. High-quality resin infiltration is achieved through high pressure, a specific cavity structure, injection port location, and good sealing. It has since been widely used in the segmented and batch preparation of composite materials. However, due to the high requirements for sealing, pressure, and injection volume required by the injection system, it has not been applied in the field of continuous composite core pultrusion technology. In order to solve the problem that conventional slotted resin baths are difficult to thoroughly infiltrate three-dimensional preforms, the present invention combines the resin injection infiltration process with the composite core pultrusion molding process, thereby forming a process system for continuously preparing a fiber-reinforced composite core with an integral structure by forming a three-dimensional preform - resin injection infiltration - pultrusion molding.

[0072] Based on this, the present invention provides a manufacturing device for a fiber-reinforced composite core, which is used to prepare a fiber-reinforced composite core with an integral structure.

[0073] like Figures 1 to 11 FIG. 1 is an embodiment of the manufacturing equipment for the fiber-reinforced composite core provided by the present invention.

[0074] See also Figure 1 and Figure 2 The manufacturing equipment of the fiber reinforced composite core of this embodiment includes a creel 1, a three-dimensional preform forming device 2, a pretreatment device, a shaping device 6 and a traction machine 7 arranged in sequence. A plurality of fiber bundles are placed on the creel 1. The three-dimensional preform forming device 2 regularly interlocks the plurality of fiber bundles alternately to form a three-dimensional preform 100. The three-dimensional preform 100 is a three-dimensional fabric. The three-dimensional preform 100 has an internal structure and an outer contour that are interwoven into one. The three-dimensional preform 100 is a non-layered integral structure. The pretreatment device pretreats the three-dimensional preform 100. The shaping device 6 impregnates the pretreated three-dimensional preform 100 with a resin 200 and pultrudes it to form a fiber reinforced composite core. The traction machine 7 provides a traction force from the creel 1 to the traction machine 7, and the traction force simultaneously pulls the fiber bundles, the three-dimensional preform 100 and the fiber reinforced composite core.

[0075] The manufacturing equipment for the fiber-reinforced composite core of this embodiment combines the molding of a three-dimensional preform 100 with the composite core pultrusion molding process, fully leveraging the continuity, low cost, high efficiency, and high-quality control characteristics of the composite core pultrusion molding process, as well as the three-dimensional preform 100's ability to effectively improve comprehensive properties such as interlayer shear resistance, impact resistance, and fatigue resistance, as well as its ability to be molded to an integrated net size. The three-dimensional preform 100 is a complete, non-layered, integral structure composed of fiber bundles without a skin-core structure. It can be molded to an integrated net size and has the distribution characteristics of multi-axial fiber reinforcement. This gives the fiber-reinforced composite core more outstanding comprehensive properties such as tensile, compressive, bending, and torsional resistance, while also combining dynamic fatigue and impact resistance, resulting in excellent comprehensive mechanical properties. Furthermore, it has the advantages of high degree of integrated structural molding, outstanding contour design capabilities, strong multi-axial performance designability, and strong strength, toughness, and light weight.

[0076] In this embodiment, preferably, continuous fiber bundles distributed along the circumferential direction are arranged on the outer contour of the three-dimensional preform 100 formed by the three-dimensional preform forming apparatus 2. These continuous fiber bundles form a part of the outer contour of the three-dimensional preform 100, constraining the internal structure of the three-dimensional preform 100 and interweaving with the internal structure of the three-dimensional preform 100 to form an integral whole, without forming a skin-core structure.

[0077] In this embodiment, the three-dimensional preform forming apparatus 2 uses a three-dimensional weaving process to prepare the three-dimensional preform 100, which includes a three-dimensional textile machine. During preparation, fiber bundles are used as yarns. By combining techniques such as yarn opening configuration, yarn specification configuration, and continuous weft weaving, the three-dimensional preform 100 can be formed into an integrated net size, so that the resulting three-dimensional preform 100 has the basic net size profile of the target composite core. It should be noted that the three-dimensional weaving process is a mature existing process. However, when preparing the three-dimensional preform 100 in the fiber-reinforced composite core manufacturing equipment of this embodiment, to facilitate resin infiltration and pultrusion of the three-dimensional preform 100, the three-dimensional weaving process and the three-dimensional textile machine can be optimized and adjusted to obtain a three-dimensional preform 100 that is as close to a round rod shape as possible and has a relatively uniform internal structure.

[0078] Specifically, the structure of the three-dimensional preform 100 obtained by forming the fiber bundle through the three-dimensional weaving process is as follows: Figure 3 and Figure 4As shown. The fiber bundle is divided into warp yarn 101 and weft yarn 102 as yarns. The warp yarn 101 extends along the pultrusion direction (warp direction) of the composite core, and the weft yarn 102 extends along the direction perpendicular to the warp direction (weft direction) in the horizontal plane. In the three-dimensional weaving process, the warp yarn 101 overlaps the weft yarn 102 of different layers by bending. After regular cycles, the cross-sections of the weft yarn 102 are stacked to achieve an overall structure of interlocking layers, that is, a three-dimensional preform 100 is obtained. In practice, the warp yarn 101 and the weft yarn 102 are bent to each other, but the degree of bending of the warp yarn 101 is smaller than that of the weft yarn 102. This is because the warp yarn 101 is subjected to greater traction. The overall structure of the three-dimensional preform 100 can be freely designed by changing the number of yarn bending points and the span of the yarn bending points. The fewer the yarn bending points and the larger the span of the yarn bending points, the stronger the deformation ability of the three-dimensional preform 100, and the better the mechanical properties along the yarn extension direction. The three-dimensional textile machine 300 is a device that regularly interlocks the warp yarn 101 and the weft yarn 102 in a three-dimensional weaving process. It is an existing device, and its structure is shown in FIG. Figure 5 As shown, during operation, the yarn (fiber bundle) passes through the heald holes of the three-dimensional textile machine 300 and the reed 301 and is then formed. The heald holes of the existing three-dimensional textile machine 300 are arranged in a spatial rectangular shape, and the heald holes of the three-dimensional textile machine 300 move up and down. The upward movement can drive the fiber bundle to be lifted, and the lifted fiber bundle and the unlifted fiber bundle form a triangular opening. After the weft yarn 102 is introduced into the opening, the reed 301 pushes the weft yarn 102 into the triangular opening for tightening, and then the lifted fiber bundle descends, and the original unlifted fiber bundle is lifted, and this cycle repeats, forming a cross-interlocking structure between the fiber bundles. In this embodiment, the heald holes of the three-dimensional textile machine 300 are preferably designed to be tilted front and back and left and right to reduce friction between the yarns. In this embodiment, a fiber bundle preforming and bundling device 400 is provided on the rear side of the yarn cloth area 302 at the rear end of the three-dimensional textile machine 300, as shown in FIG. Figure 6As shown, the fiber bundle preforming and bundling device 400 is equipped with several grids, each of which can constrain a line of fiber bundles, and each grid corresponds one-to-one to a heald hole of the three-dimensional textile machine 300. Based on the target composite core diameter, fiber volume content, linear density, and bulk density of the fiber raw material, the required number of fiber bundles can be calculated. After comprehensively considering the target composite core diameter and the warp distribution points of the three-dimensional textile machine, a square grid is formed on the fiber bundle preforming and bundling device 400. Based on the fiber bundle usage, a circle is drawn within the square grid. The area within the circle serves as the yarn distribution area, and the required number of fiber bundles is evenly arranged within the circle. Fiber bundles are first arranged in the complete individual cells within the circle. At the edge of the circle, fiber bundles are arranged in the cells whose area within the circle exceeds two-thirds of the individual cell area. Fiber bundles are not arranged in the cells whose area within the circle is less than one-third of the individual cell area. At the stage when the fiber bundle is initially formed into a three-dimensional preform, the fiber bundle preforming and bundling device 400 is placed on the rear side of the yarn cloth area 302 of the three-dimensional textile machine 300. After the fiber bundle passes through the heald wire hole and the reed 301 of the three-dimensional textile machine 300, it passes through the fiber bundle preforming and bundling device 400 and is constrained in the yarn cloth area on the square grid of the fiber bundle preforming and bundling device 400. When the fiber bundle is formed into a three-dimensional preform 100 by the three-dimensional textile machine 300, the fiber bundle preforming and bundling device 400 is pulled at the rear side of the three-dimensional preform 100. The fiber bundles are guided forward synchronously; as the molding length of the three-dimensional preform 100 in front of the fiber bundle preforming and bundling device 400 continues to increase, when the fiber bundles not involved in the molding and the molded three-dimensional preform portion are able to pass through the subsequent path and be pulled and held by the traction force, the fiber bundle preforming and bundling device 400 is disassembled, and the fiber bundle preforming and bundling device 400 is withdrawn from the fiber bundle advancement path, so that the molded three-dimensional preform 100 can smoothly enter the next process, and the three-dimensional textile machine 300 continues to mold the three-dimensional preform 100 under the traction force. As a result, the fiber bundle preforming and bundling device 400 plays a preforming and bundling function for the initial molding of the fiber bundles, which can ensure the straightness and contour molding quality of the three-dimensional preform 100, improve the circular fit between the outer contour of the three-dimensional preform 100 and the target composite core, and obtain a three-dimensional preform 100 with a shape close to the target composite core shape.

[0079] Figure 7The figure shows the yarn threading pattern of a cross-sectional structure of a three-dimensional preform 100 formed using a three-dimensional weaving process. Weft yarns 102a are arranged circumferentially along the outer contour of the three-dimensional preform 100. These weft yarns 102a are continuous fiber bundles distributed circumferentially along the outer contour of the three-dimensional preform 100. The continuous weft yarns 102a interlock different warp yarn layers and form a circumferential fiber bundle on the surface layer. The weft yarns 102a extend in different directions, and their paths continue after passing around the warp yarns 101 arranged at the edge of the circle. The continuous weft yarn 102a structure constrains the warp yarns 101 in a quasi-entanglement manner along the circumference of the three-dimensional preform 100, further achieving a unified and non-stratified internal structure and outer contour of the three-dimensional preform 100. The closed weft yarn loops formed at the edges of different warp yarn layers are one of the foundations of the integrated molding of the three-dimensional preform 100. In particular, in actual operation, additional fine tension yarns may be added at the warp yarn arrangement points at the circular edge or the tension of the warp yarns at the circular edge points may be increased to improve the molding quality of the three-dimensional preform 100 .

[0080] Figure 8 The cross-sectional structure of a fiber-reinforced composite core with a monolithic structure, produced from a three-dimensional preform 100 formed using a three-dimensional weaving process, is shown. When the preform 100 is impregnated with resin 200, the fiber bundles on the outer surface of the preform 100 are covered by the resin 200, forming a resin surface layer 201. The resin 200 then enters the interior of the preform 100, filling the spaces between the fiber bundles and forming a resin filling layer 202. The preform 100, impregnated with resin 200, is then pultruded and cured to form a fiber-reinforced composite core with a monolithic structure.

[0081] It should be noted that Figure 7 and Figure 8 To illustrate the layers of warp yarns 101, weft yarns 102, and resin 200, the layers are shown with elliptical cross-sections, solid lines, and dashed lines, respectively. In practice, both warp yarns 101 and weft yarns 102 are irregular, ribbon-like fiber bundles that, after regular alternating interlocking, form a roughly oblate shape. During pultrusion of the three-dimensional preform 100, the fiber bundles move relative to each other to fill larger voids within the preform's internal structure, with resin 200 further filling all of these voids. To distinguish the layers of warp yarns 101, weft yarns 102, and resin 200, the boundaries and positions of the warp yarns 101, weft yarns 102, and the circumferentially distributed fiber bundles and resin 200 on the outer contour are enlarged for clarity.

[0082] Therefore, in a preferred embodiment, the three-dimensional preform forming device 2 includes a three-dimensional textile machine 300 and a fiber bundle preforming and bundling device 400. Figure 1When the manufacturing equipment of the fiber reinforced composite core of this embodiment is working, the fiber bundle is used as the yarn (warp yarn 101 and weft yarn 102), and the fiber bundle is placed on the creel 1 in a wound state wound on a reel. Under the traction force of the traction machine 7, the fiber bundle is unwound from the reel in a single bundle shape, introduced into the three-dimensional preform forming device 2 through the ceramic eye, and after passing through the heald wire hole and the reed 301 of the three-dimensional textile machine 300, it is formed into a three-dimensional preform 100 with a shape close to the target composite core shape. In the initial stage of forming, the fiber bundle preforming and bundling device 400 is placed on the rear side of the yarn laying area 302 of the three-dimensional textile machine 300 to preform and bundle the fiber bundle. After a certain length of the three-dimensional preform is formed, when the fiber bundle that does not participate in the forming and the formed three-dimensional preform part can pass through the subsequent path and be pulled and held by the traction force, the fiber bundle preforming and bundling device 400 is disassembled and exits the fiber bundle forward path. In this way, the integrated net size molding of the three-dimensional preform 100 is achieved, and the obtained three-dimensional preform 100 has the basic net size profile of the target composite core.

[0083] In this embodiment, the fiber bundle can be any one or more combinations of carbon fiber, glass fiber, ultra-high molecular weight polyethylene fiber, aramid fiber, polyimide fiber, PBO fiber (short for poly(p-phenylene benzobisoxazole) fiber), hybrid fiber (a mixture of multiple different fibers), modified fiber (such as a fiber with carbon nanotubes, toughening particles, or other substances introduced into the surface of an existing fiber to improve certain properties), and plant fiber (such as lignin fiber). The fiber-reinforced composite core of this embodiment is primarily used in cables, so the fiber bundles used are primarily carbon fiber.

[0084] See also Figure 1 In the manufacturing equipment of the fiber reinforced composite core of this embodiment, preferably, the pretreatment device includes a preforming device 3, a preheating device 4 and a compression device 5 arranged in sequence along the traction direction of the traction force of the traction machine 7, the preforming device 3 performs a primary compression on the three-dimensional preform 100 prepared by the three-dimensional preform forming device 2, the preheating device 4 preheats the three-dimensional preform 100 after the primary compression, and the compression device 5 performs a secondary compression on the preheated three-dimensional preform 100.

[0085] Among them, see Figure 9Preferably, the preforming device 3 includes two preforming opening and closing portions 31 that are arranged opposite each other and can be separated or joined along the compression direction A of the primary compression. A preforming cavity 32 is formed between the two joined preforming opening and closing portions 31 and extends along the traction direction of the traction force. The preforming cavity 32 includes a preforming straight section 32a having a diameter smaller than the outer diameter of the three-dimensional preform 100 and a preforming bell-shaped section 32b extending from both ends of the preforming straight section 32a and having a gradually increasing diameter. As the three-dimensional preform 100 passes through the preforming cavity 32 of the preforming device 3, the two preforming opening and closing portions 31 regularly separate and join, shaping the three-dimensional preform 100 to a relatively uniform target diameter through the preforming straight section 32a of the preforming cavity 32. The opening and closing speed of the preforming device 3 is coordinated with the forward speed of the three-dimensional preform 100, so that the length of each pressing can overlap from beginning to end, avoiding omissions. The length of the preforming cavity 32 of the preforming device 3 is related to the target diameter. The larger the target diameter, the longer the preforming cavity 32 should be and the more points of force for opening and closing should be added to ensure uniform compression force. The preforming bell-mouth sections 32b at both ends of the preforming cavity 32 can facilitate the introduction and export of the three-dimensional preform 100 into the preforming cavity 32. Preferably, the two preforming bell-mouth sections 32b and the preforming straight section 32a are smoothly connected by chamfers to avoid sharp edges or corners that may damage the three-dimensional preform 100 and to avoid large indentations. Preferably, the cavity wall of the preforming cavity 32 is provided with a coating to improve the wear resistance of the preforming cavity 32 and reduce the friction coefficient.

[0086] The preheating device 4 can adopt an existing conventional heating device.

[0087] See also Figure 10Preferably, the compression device 5 includes two compression opening and closing sections 51 that can be separated or joined relative to each other along the compression direction B of the secondary compression. A compression chamber 52 extending in the pulling direction of the traction force is formed between the two joined compression opening and closing sections 51. The compression chamber 52 includes a compression straight section 52a having a diameter no greater than the outer diameter of the three-dimensional preform 100 after the primary compression, and compression bell-mouth sections 52b extending from both ends of the compression straight section 52a and having gradually increasing diameters. When the preheated three-dimensional preform 100 passes through the compression chamber 52 of the compression device 5, the two compression opening and closing sections 51 regularly separate and join, and the three-dimensional preform 100 is subjected to a second-stage shaping to the target diameter by the compression straight sections 52a of the compression chamber 52. This further compresses the abundant elastic relaxation space within the three-dimensional preform 100 to ensure the fiber volume content and molding quality of the final composite core, and to ensure that the shape of the three-dimensional preform 100 approximates the target composite core shape. The opening and closing speed of the compression device 5 is coordinated with the forward speed of the three-dimensional preform 100, so that the length of each pressing can overlap from beginning to end to avoid omissions. The length of the compression chamber 52 of the compression device 5 is related to the target diameter. The larger the target diameter, the longer the compression chamber 52 should be and the more points of force for opening and closing should be added to ensure uniform compression force. The compression bell-mouth sections 52b at both ends of the compression chamber 52 can facilitate the introduction and export of the three-dimensional preform 100 into the compression chamber 52. Preferably, the two compression bell-mouth sections 52b and the compression straight section 52a are smoothly connected by chamfers to avoid sharp edges or corners that may damage the three-dimensional preform 100 and to avoid large indentations. Preferably, the wall of the compression chamber 52 is provided with a wear-resistant and anti-stick coating to improve the wear resistance of the compression chamber 52 and reduce the friction coefficient.

[0088] Furthermore, the compression device 5 can also pre-impregnate the preheated three-dimensional preform 100 with resin while performing secondary shaping on the preheated three-dimensional preform 100. The resin pre-impregnation is preferably performed by pressure injection of the resin into the three-dimensional preform 100. Figure 10In a preferred embodiment, at least one compression opening and closing portion 51 of the compression device 5 is provided with a first resin injection port 53 in communication with the compression chamber 52. The first resin injection port 53 is used to pressure-inject resin into the compression chamber 52. The first resin injection port 53 is connected to a resin injection system, which is an existing device. A resin recovery device can be provided below the compression device 5 to receive excess resin squeezed out of the compression device 5. During each opening and closing of the compression device 5, resin is injected into the compression chamber 52 through the first resin injection port 53. Under the injection pressure, the resin infiltrates into the three-dimensional preform 100. Furthermore, due to the closed compression force of the compression device 5 and the capillary effect, the resin gradually diffuses within the three-dimensional preform 100, forming a preliminary infiltration. Excess resin is squeezed out of the compression device 5, recovered and filtered by the recovery device below the compression device 5, and then returned to the resin injection system, thereby achieving secondary shaping and resin pre-infiltration of the three-dimensional preform 100. Preferably, a first resin injection port 53 is respectively provided on the two compression opening and closing parts 51. The two first resin injection ports 53 are respectively located at the two ends of the compression straight section 52a and are arranged in a counter-position along the compression direction B of the secondary compression. Through the pressure offset of the two counter-positioned first resin injection ports 53, the three-dimensional preform 100 can be thoroughly infiltrated and the resin overflow from the fracture of the compression device 5 can be slowed down.

[0089] Therefore, in step 2, the shape of the three-dimensional preform 100 after secondary shaping and resin pre-impregnation by the compression device 5 is similar to the target shape of the fiber-reinforced composite material, and the resin 200 is diffused in the internal structure of the three-dimensional preform 100 after secondary shaping and resin pre-impregnation by the compression device 5 to form preliminary resin impregnation.

[0090] In this embodiment, preferably, the compression direction A of the primary compression performed by the preforming device 3 on the three-dimensional preform 100 and the compression direction B of the secondary compression performed by the compression device 5 on the three-dimensional preform 100 are perpendicular to each other. Preferably, the compression direction A of the primary compression is horizontal, and the compression direction B of the secondary compression is vertical. The perpendicular compression directions of the two shaping processes can neutralize indentation deformation, making the cross-section of the three-dimensional preform 100 after the secondary shaping process fuller.

[0091] See also Figure 1 and Figure 11In the fiber-reinforced composite core manufacturing apparatus of this embodiment, the shaping device 6 preferably uses pressure injection of resin to impregnate the pretreated three-dimensional preform 100 with resin. Preferably, the shaping device 6 includes a shaping mold 61 having a shaping cavity 62 formed therein, extending along the pulling direction of the traction force. The shaping mold 61 is provided with a second resin injection port 63 communicating with the shaping cavity 62 and a high-temperature curing zone for heating the interior of the shaping cavity 62. The second resin injection port 63 is used for pressure-injecting resin into the shaping cavity 62. The high-temperature curing zone is located on the side of the second resin injection port 63 away from the compression device 5 and closer to the tractor 7. The shaping cavity 62 of the shaping mold 61 is relatively long, and the end of the shaping cavity 62 near the compression device 5 is configured to expand outwardly into a trumpet shape to facilitate the entry of the pretreated three-dimensional preform 100 into the shaping cavity 62 of the shaping mold 61. After pretreatment and secondary compression molding by the compression device 5, the three-dimensional preform 100 can more easily enter the shaping mold 61 of the shaping device 6. The second resin injection port 63 can be connected to the resin injection system through the mixing head 64, and the resin injection system is an existing device. When the pretreated three-dimensional preform 100 passes through the shaping cavity 62 of the shaping mold 61, the resin in the resin injection system completes the first degassing under ultrasonic waves, and is injected into the shaping cavity 62 through the second resin injection port 63 under high pressure to complete the final injection infiltration of the three-dimensional preform 100. Preferably, an ultrasonic transmitter is arranged outside the resin infiltration area of ​​the shaping mold 61 where the second resin injection port 63 is located. After setting a certain frequency, the ultrasonic wave penetrates the three-dimensional preform 100 and the infiltrated resin, thereby further promoting the degassing of the resin injected into the three-dimensional preform 100 and reducing the internal porosity of the composite core. The finally impregnated three-dimensional preform 100 is heated in a high-temperature curing zone to cure the three-dimensional preform 100 impregnated with resin and finally pulled out of the shaping mold 61 to obtain a fiber-reinforced composite core with an integral structure.

[0092] Preferably, in this embodiment, a collection system for collecting the fiber-reinforced composite core is provided between the shaping device 6 and the traction machine 7. The fiber-reinforced composite core pulled out from the shaping mold 61 is collected by the collection system after being cooled, and the collection method is preferably coil collection.

[0093] In this embodiment, the resin 200 impregnated with the three-dimensional preform 100 may be any one of a thermoplastic resin and a thermosetting resin, or a combination of the two (eg, toughening particles of thermoplastic resin added to thermosetting resin).

[0094] See also Figure 1In the manufacturing equipment for the fiber-reinforced composite core of this embodiment, a traction machine 7 provides a pulling force from the creel 1 to the collection system, thereby pulling the fiber bundle, the three-dimensional preform 100, and the fiber-reinforced composite core forward, so that the preparation process of the fiber-reinforced composite core proceeds continuously. Specifically, the traction machine 7 sequentially pulls the fiber bundle on the creel 1 through the three-dimensional preform forming device 2 (three-dimensional textile machine 300 and fiber bundle preform bundling device 400) to form the three-dimensional preform 100. The three-dimensional preform 100 is then pulled through the preforming device 3 for a primary compression molding to a relatively uniform target diameter. It is then preheated through the preheating device 4. It is then compressed and molded into a composite core shape that approximates the target diameter and is initially impregnated with resin through the compression device 5. The resin is finally injected and infused and cured through the shaping device 6 to form the fiber-reinforced composite core. The fiber-reinforced composite core is then pulled out of the shaping device 6, cooled, and then enters the collection system. This forms a continuous preparation process system of three-dimensional preform molding, resin injection and infiltration, and pultrusion molding, thereby producing a fiber-reinforced composite core with an integral structure.

[0095] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A manufacturing device for a fiber-reinforced composite core, characterized in that: The invention comprises a yarn rack, a three-dimensional preform forming device, a pretreatment device, a shaping device and a traction machine arranged in sequence, wherein a plurality of fiber bundles are placed on the yarn rack; the three-dimensional preform forming device regularly interlocks the plurality of fiber bundles to form a three-dimensional preform, wherein the three-dimensional preform is a three-dimensional fabric, wherein the three-dimensional preform has an internal structure and an outer contour interwoven into one, and the three-dimensional preform is a non-layered integral structure; the pretreatment device pretreats the three-dimensional preform, wherein the pretreatment device comprises a preforming device, a preheating device and a compression device arranged in sequence along the traction direction of the traction force, wherein the preforming device The three-dimensional preform prepared by the body forming device is compressed once, the preheating device preheats the three-dimensional preform after the once compression, and the compression device compresses the preheated three-dimensional preform for a second time, and the compression direction of the three-dimensional preform by the preforming device for the first compression is perpendicular to the compression direction of the three-dimensional preform by the compression device for the second compression; the shaping device impregnates the pretreated three-dimensional preform with resin and pultrudes it to form a fiber-reinforced composite core; the traction machine provides a traction force from the yarn frame to the traction machine, and the traction force simultaneously pulls the fiber bundle, the three-dimensional preform and the fiber-reinforced composite core.

2. The manufacturing equipment of the fiber reinforced composite core according to claim 1, characterized in that: The three-dimensional preform forming device includes a three-dimensional textile machine.

3. The manufacturing equipment of the fiber reinforced composite core according to claim 1, characterized in that: The preforming device includes two preforming opening and closing parts that can be separated or connected to each other along the compression direction of the primary compression, and a preforming cavity that passes through along the traction direction of the traction force is formed between the two connected preforming opening and closing parts. The preforming cavity includes a preforming straight section with a diameter smaller than the outer contour diameter of the three-dimensional preform and a preforming trumpet section with a gradually increasing diameter extending from both ends of the preforming straight section.

4. The manufacturing equipment of the fiber reinforced composite core according to claim 3, characterized in that: The cavity wall of the preforming cavity is provided with a plating layer.

5. The manufacturing equipment of the fiber reinforced composite core according to claim 1, characterized in that The compression device includes two compression opening and closing parts that can be separated or connected to each other along the compression direction of the secondary compression, and a compression chamber that passes through along the traction direction of the traction force is formed between the two connected compression opening and closing parts. The compression chamber includes a compression straight section with a diameter not greater than the outer contour diameter of the three-dimensional preform after the first compression and a compression bell-mouth section with a gradually increasing diameter extending from both ends of the compression straight section.

6. The manufacturing equipment for fiber-reinforced composite core according to claim 5, characterized in that: A first resin injection port is respectively provided on the two compression opening and closing parts. The two first resin injection ports are respectively located at the two ends of the compression straight section and are arranged in a counter-positioned manner along the compression direction of the secondary compression. The two first resin injection ports are used to pressure-inject resin into the compression cavity.

7. The manufacturing equipment of the fiber reinforced composite core according to claim 1, characterized in that The shaping device includes a shaping mold, a shaping cavity is formed inside the shaping mold and passes through along the traction direction of the traction force, the shaping mold is provided with a second resin injection port connected to the shaping cavity and a high-temperature curing zone for heating the interior of the shaping cavity, the second resin injection port is used to pressure-inject resin into the shaping cavity, and the high-temperature curing zone is located on the side of the second resin injection port close to the traction machine.

8. The manufacturing equipment of the fiber reinforced composite core according to claim 1, characterized in that: A collecting system for collecting the fiber-reinforced composite core is provided between the shaping device and the traction machine.

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