A continuous internal thread structure fiber composite material preform and preparation method thereof

Abstract

The present invention proposes a continuous internal thread structure fiber composite material preform and a preparation method thereof. The present invention uses a strand of coarse fiber as the overall internal thread part (1), and the internal thread extends numerous "tentacles" to tightly grasp the annular support column (2) outward, and each point of the continuous internal thread is fixed on the annular support column (2). When the screw is transferred into the internal thread and starts to work, when it is subjected to shear force, the annular plain cloth of the annular support column (2) forms a continuous fiber to generate a counter force to offset the shear force; when it receives a tensile force, the force is first generated on the continuous fiber of the internal thread, and then transmitted to each "tentacle", each "tentacle" grasps the annular support column (2), and each point of the annular support column (2) is subjected to a force toward the center of the circle, thereby causing the entire internal thread structure to produce an invisible inward contraction deformation, squeezing the screw, so that the screw and the entire internal thread structure are more tightly combined.

Description

Technical Field

[0001] The present invention relates to the technical field of high-stability bonding of composite materials, and in particular to a continuous internal thread structure fiber composite material preform and a preparation method thereof. Background Art

[0002] Fiber-reinforced ceramic matrix composites have excellent properties such as low density, high specific modulus, high specific strength, low thermal expansion coefficient, and thermal shock resistance, which make them have great application potential in the aerospace field. Lightweight and high stability of structural parts are key factors in realizing the application of ceramic matrix composites in the aerospace field.

[0003] Screw structures are frequently used in the aerospace field for quick assembly. Different prefabricated structure designs and weaving techniques can produce completely different effects. The present invention achieves a high-strength and high-stability screw structure by studying a new prefabricated weaving method.

[0004] In the field of composite materials, the traditional method for preparing internal threads is to first manufacture the component and then machine the component to make the internal threads. The internal threads prepared by machining will destroy the continuity of the fibers, exposing part of the fibers of the internal threads, affecting the strength and service life of the component. Moreover, the machined threads are easily worn out by the broken fibers under the action of shear and tensile forces for a long time, resulting in loose threads and other phenomena. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention proposes a continuous internal thread structure fiber composite material preform and a preparation method thereof. The present invention uses a strand of coarse fiber as the overall internal thread part (1), and the internal thread extends countless "tentacles" to tightly grasp the annular support column (2) outward, and each point of the continuous internal thread is fixed on the annular support column (2). When the screw is transferred into the internal thread and starts to work, when it is subjected to shear force, the annular plain cloth of the annular support column (2) forms a continuous fiber to generate a counterforce to offset the shear force; when it receives a tensile force, the force is first generated on the continuous fiber of the internal thread, and then transmitted to each "tentacle", each "tentacle" grasps the annular support column (2), and each point of the annular support column (2) is subjected to a force toward the center of the circle, thereby, the entire internal thread structure produces an invisible inward contraction deformation, squeezing the screw, so that the screw and the entire internal thread structure are more tightly combined.

[0006] A continuous internal thread structure fiber composite material preform, characterized in that: the continuous internal thread structure fiber composite material preform consists of a threaded portion (1) and an annular support column (2); the annular support column (2) is prepared by surrounding n layers of annular plain fabric, n is a positive integer not less than 2, the threaded portion (1) is formed by continuous fibers surrounding along a thread path, and the continuous fibers are divided into multiple unidirectional fibers to sew the annular support column (2).

[0007] A continuous internal thread structure fiber composite material preform and a preparation method thereof, characterized in that: firstly, a thread core mold is prepared, as shown in the figure, by melting a special material at high temperature, the thread core mold is composed of a thread body (3) and a snap cap (4), and the snap cap (4) is on both sides of the thread body (3); a thread fiber cloth is prepared, the thread fiber cloth is prepared by removing part of the warp and weft fibers of a plain cloth; the warp fibers of the thread fiber cloth are bundled into a strand, wrapped around the groove of the thread body (3), and the released fibers are all released to the outside of the thread, and the front and end fibers are limited by the snap cap (4) to prepare thread fibers; the released fibers are bundled into a strand as stitching fibers, which are circumferentially wrapped around n layers of plain cloth, and the circumferentially wrapped plain cloth is stitched. The threaded part (1) is made of plain cloth with both warp fibers removed, the weft fibers are released, and multiple strands of fibers are left in the middle.

[0008] The multiple strands of fibers are assembled into a bundle of fibers, and the number of the assembled bundle of fibers is sufficient to fill the groove portion of the thread core mold.

[0009] The weft fibers released by the threaded portion (1) are symmetrical, and the length of the weft fibers released on one side is greater than the wall thickness of the annular support column (2).

[0010] The threaded portion (1) is made of plain cloth, and fibers on both sides of the weft direction are removed to release the warp direction fibers. The released warp direction fibers act on the buckle cap (4) to limit the threaded structure fibers.

[0011] The length of the threaded portion (1) of the plain fabric where the weft fibers have not been removed is equal to the length of the threaded core mold groove portion.

[0012] The n weft fibers released unilaterally are assembled into one strand to serve as suture fibers.

[0013] N layers of square plain woven fabric are prepared, wrapped around the spiral body (3), and the fibers are stitched to form the square plain woven fabric.

[0014] The thickness of the square plain weave cloth is 0.3-0.35mm. Each time a layer is laid in the annular direction, the circumference of the layer increases by 0.9-1.1mm.

[0015] The sewing method is not limited to the double-strand two-way lock stitching process, the single-strand oblique stitching process, the single-strand through stitching process, and the single-strand hook stitching process.

[0016] The annular support column (2) may be in a square, conical, irregular or other shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an overall schematic diagram of the internal thread structure of the present invention;

[0018] Figure 2It is an overall schematic diagram of the thread core mold of the present invention;

[0019] Figure 3 A schematic diagram of a plain weave fabric required for the internal threaded portion of the present invention;

[0020] Figure 4 It is an overall schematic diagram of the internal thread of the present invention being wound on the thread core mold;

[0021] Figure 5 A top view of the internal thread of the present invention being wound on a thread core mold;

[0022] Figure 6 It is a top view of the hoop-wound plain weave fabric of the present invention. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0024] like Figure 2 The threaded core mold of special organic materials is prepared as shown. The core mold will melt in an environment above 600 degrees. The diameter of the threaded core mold part is 2 cm, and the number of threads of the core mold is 10.

[0025] like Figure 3 The plain weave fabric of the threaded part (1) is shown as being made of T300-3K carbon fiber, with a horizontal length of 17 cm and a vertical length of 80 cm. The warp threads of 8.3 cm on the left and right sides are removed horizontally to release the weft threads of 8.3 cm; the weft threads of 7.6 cm on the upper and lower sides are removed vertically to release the warp threads of 7.6 cm. The middle warp fiber specification of the plain weave fabric of the threaded part (1) is 3k, and the number of fibers filling the thread groove is 8. The 8 3K warp fibers in the middle are folded to form a bundle of coarse fibers.

[0026] like Figure 4 As shown, a small amount of organic adhesive is added to the thread groove, and the coarse fiber is wound around the thread core mold pattern until it is fully wound. While keeping the coarse fiber tightly wound, the released warp thread is clamped at the buckle cap (4). Every 4-5 adjacent strands of the released weft thread are gathered into a bundle as a suture fiber.

[0027] like Figure 6 As shown, the threaded mandrel surrounds 130 layers of T300-3K carbon fiber plain weave cloth, each layer is 0.3-0.35mm thick, and the circumference of the T300-3K carbon fiber plain weave cloth increases by 0.9-1.1mm each time it is laid, until the laying thickness is 4cm. The laid plain weave cloth is sutured by the stitching fiber, using a single-strand through-stitching process.

Claims

1. A method for preparing a continuous internal thread structure fiber composite material preform, characterized in that: The continuous internal thread structure fiber composite material preform is composed of a threaded portion (1) and an annular support column (2); The preparation method thereof is: S1. Prepare a thread core mold, wherein the thread core mold is prepared by melting a special material at a high temperature, and the thread core mold is composed of a thread body (3) and a buckle cap (4), wherein the buckle cap (4) is on both sides of the thread body (3); S2, preparing a threaded fiber cloth, wherein the threaded fiber cloth is prepared by removing the fibers on both sides of the warp direction of a plain weave cloth, releasing the weft direction fibers, leaving a plurality of warp direction fibers in the middle, removing the fibers on both sides of the weft direction, and releasing the warp direction fibers; S3, a bundle of warp fibers of the threaded fiber cloth is gathered and wrapped around the groove of the threaded body (3), and the released weft fibers are all released to the outside of the threaded body (3), and the front and rear ends of the warp fibers are limited by the buckle cap (4), thereby preparing the threaded portion (1); S4, the released weft fiber m strands are bundled into one strand as a stitching fiber; the hoop-wound spiral body (3) is annularly wound with n layers of plain weave cloth, where n is a positive integer not less than 2; the stitching fiber stitches the hoop-wound plain weave cloth.

2. The method for preparing a continuous internal thread structure fiber composite material preform according to claim 1, characterized in that: The multiple strands of warp fibers remaining in the middle are assembled into a bundle of fibers, and the number of the bundle of fibers assembled from the multiple strands of warp fibers is sufficient to fill the groove portion of the thread core mold.

3. The method for preparing a continuous internal thread structure fiber composite material preform according to claim 1, characterized in that: The weft fibers released by the threaded portion (1) are symmetrical, and the length of the weft fibers released on one side is greater than the wall thickness of the annular support column (2).

4. The method for preparing a continuous internal thread structure fiber composite material preform according to claim 1, characterized in that: The length of the unremoved weft fiber portion of the threaded portion (1) is equal to the length of the threaded core mold groove portion.

5. The method for preparing a continuous internal thread structure fiber composite material preform according to claim 1, characterized in that: N layers of square plain woven fabric are prepared, wrapped around the spiral body (3), and the fibers are stitched to form the square plain woven fabric.

6. The method for preparing a continuous internal thread structure fiber composite material preform according to claim 1, characterized in that: The annular support column (2) is square or conical.

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