Prefabricated body with annular cavity and preparation method of prefabricated body

Abstract

The cavity circular-ring-shaped prefabricated body and the preparation method thereof are characterized in that the circular-ring-shaped prefabricated body is formed in the mode that a certain number of rib positions are added into a cavity disc, and under the technology, the high strength of the disc is achieved, and the extremely high lightweight effect is achieved. The metal mold is adopted for limiting and preparing the rib position, continuity of the rib position and the main body is ensured, sewing of the rib position and the main body component in the preparation process is facilitated, and the steps of the prefabricated body preparation process are reduced. According to the method, the fiber cloth in a specific shape is cut, the three surfaces of the prefabricated body are kept continuous, namely, the continuity of the main body is kept, the integrated effect is kept, and the strength of the whole prefabricated body component is further enhanced.

Description

Technical Field

[0001] The present application relates to the field of aerospace equipment manufacturing, and in particular to a hollow annular preform and a preparation method thereof. Background Art

[0002] Advanced composite materials are increasingly used in modern industry and technology due to their excellent physical properties and chemical stability. These materials are usually made of high-performance fibers, such as carbon fiber, glass fiber or aramid fiber, and matrix materials such as resin, ceramic or metal through a specific process. They not only have the characteristics of high strength and light weight, but also have excellent fatigue resistance, impact resistance and corrosion resistance. These characteristics make them indispensable materials in fields with high performance requirements, such as aerospace, automobile manufacturing, sports equipment and building structures.

[0003] In the design and manufacturing process of aerospace vehicles, the disc base is a key component that supports and connects other structural components. Its performance is directly related to the stability and reliability of the entire vehicle. Since the disc base needs to withstand huge dynamic and static loads and complex stress states, including tension, compression, bending and torsion, the requirements for materials are extremely high. Advanced composite materials, with their light weight and high strength, are ideal for manufacturing such structural components. However, at present, the manufacturing of large structural parts such as disc bases is still a major technical challenge due to their design complexity and processing technology limitations.

[0004] Patent No. 2012103780307 discloses a technology for using carbon fiber composite material connectors to connect back ribs and reflective surfaces to form a low expansion mesh reflector (x). This technology uses the same material as the main body of the structural component to manufacture the connector, which can indeed have good structural strength while also having a thermal expansion coefficient that matches the main body, and can effectively reduce local thermal deformation of the component. However, this method requires the preparation of additional connectors on the basis of preparing the main component, which greatly increases the production cost and complexity. Summary of the invention

[0005] A hollow annular preform and a preparation method thereof, by combining mold design and rib preparation technology, obtains a convenient and efficient preparation technology, characterized in that: S1, preparing a complete set of circular ring molds, wherein the circular ring molds include a column sheet (1), a single sector mold (2), a base mold (3), a stitching mold (4), and a disc mold (5); S2, cutting a rectangular fiber cloth, folding it in a wave shape in one direction until the width is equal to the height of the column sheet (1), and simply stitching the folded rectangular fiber cloth; unfolding the fiber cloth at the stitching connection and folding it in a wave shape, stacking the rectangular fiber cloth at the stitching connection according to the wave folding marks, folding it in a wave shape, and then stitching it; S3, the disc mold (5) is embedded in the single sector mold (2), the strip fiber cloth is wrapped around the sector column piece and sewed to connect, and this step is repeated for all single sector molds (2); S4, all the single sector molds (2) are fixed to the base mold (3), a disc mold (5) is placed in the middle, and the rib connection between the sectors is sewn; S5, cutting n pieces of three-arc strip fiber cloth, where n is a positive integer; the three-arc strip fiber cloth is divided into three areas 11, 12, and 13, where area 11 is an arc-shaped long strip, area 12 is a fan-shaped long strip, and area 13 is an arc-shaped short strip; the two sides of the arc-shaped long strip in area 11 are parallel, and the lengths of the two sides of the arc-shaped long strip are equal to the height of the column piece (1), and the arc lengths are equal; the two sides of the arc-shaped short strip in area 13 are parallel, and the lengths of the two sides of the arc-shaped long strip are equal to the height of the column piece (1), and the arc lengths are equal; area 12 is a fan-shaped structure, and the fan-shaped radius is equal to the fan-shaped radius of the rectangular fiber cloth surrounded by the single fan-shaped mold (2), the longer arc side of the fan-shaped is connected to area 11, and the arc length is shared, and the shorter arc side of the fan-shaped is connected to area 13, and the arc length is shared.

[0006] S6, in the single sector mold (2), all the column pieces (1) are pulled out in sequence, and the pieces are placed into the stitching mold (4), and the disc mold (5) is removed; S7, the cut fiber cloth is folded to cover the vertical surface and the upper circular surface of the whole set of circular ring molds, and the vertical surface is sewed with the strip fiber cloth.

[0007] Furthermore, the column piece (1) is removable on the fan-shaped mold (2).

[0008] Furthermore, the thickness of the folded rectangular fiber cloth at the stitching connection is twice as thick.

[0009] Furthermore, the fibers at the stitching connection are arranged at the rib position, and the size of the fiber cloth at the stitching connection is the same as the size between the two column pieces on one side of the single sector mold (2).

[0010] Furthermore, the thickness of the rib connection between the sectors is the sum of 1 times the thickness of the strip fiber cloth and 2 times the thickness of the strip fiber cloth, and the thickness of the rib connection is equal to the distance between the column sheets (1) between adjacent sectors.

[0011] Furthermore, the main body of the stitching mold is used to support the fan-shaped radius of the fan-shaped structure; the support part of the stitching mold supports the fan-shaped arc of the fan-shaped structure, and the support part provides a stitching space for the stitching process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description: Figure 1 It is a structural diagram of a hollow circular ring preform; Figure 2 It is a top view of the hollow circular ring preform; Figure 3 Prepare a completed drawing for the tendon position; Figure 4 This is a structural diagram of a single-sector mold; Figure 5 It is a single fan-shaped mold assembly diagram; Figure 6 This is a diagram of the stitching mold structure; Figure 7 This is the disc mold structure diagram; Figure 8 Cutting fiber cloth structure diagram for S5. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below through examples so that those skilled in the art can implement the invention with reference to the description.

[0014] S1. Prepare a complete set of circular ring molds, which include a column piece (1), a single sector mold (2), a base mold (3), a stitching mold (4), and a disc mold (5).

[0015] All molds are made of stainless steel. The column piece (1) can be plugged into the single fan-shaped mold (2). The single sector mold (2) is connected to the base mold via screws, the disc mold (5) is used to be placed in the circular hole formed by the single sector mold (2), and the stitching mold (4) can replace the column sheet (1) to shape the fiber cloth.

[0016] S2. Cut a rectangular fiber cloth, fold it in a wave shape in one direction until the width is equal to the height of the column sheet (1), and simply sew the folded strips of fiber cloth.

[0017] Cut 6 pieces of rectangular carbon fiber cloth with an aspect ratio of 0.8:2. Fold the carbon fiber cloth in a wave shape at the 0.8 length position, fold the single piece of fiber cloth 3 times to form 4 wave surfaces, overlap the wave surfaces, and simply sew the middle part to prepare 6 fiber strips with an aspect ratio of 0.2:2 and a thickness of 1.2 mm.

[0018] S3, the disc mold (5) is embedded in the single sector mold (2), and the strip fiber cloth is wrapped around the sector column piece for stitching and connection, and this step is repeated for all the single sector molds (2).

[0019] Take a single fan-shaped mold (2) with a column sheet (1) installed, the height of the column sheet is also 0.2, the fiber strip surrounds the column sheet (1) to form a fan shape, and the inner circle part is placed in a disc mold (5) to press out an arc strip. While maintaining the fan shape of the fiber strip surrounding the city, there is still fiber surplus for stitching, the front and end of the fiber strip are slightly spread out and folded in waves, the head and tail are overlapped in waves, the size of the overlapping part is the same as the size of one side of the fan, and the overlapping part is placed on one side of the fan, and simple stitching is performed, and this step is repeated 5 times. Because the fiber thickness of the wave-shaped overlapping part is twice that of the fiber strip, it is necessary to ensure that the overlapping surface is placed on the same side each time to ensure the uniformity of the final structure.

[0020] S4, all the single sector molds (2) are fixed to the base mold (3), a disc mold (5) is placed in the middle, and the rib connections between the sectors are sewn.

[0021] like Figure 5 As shown, all the single-sector molds (2) are fixed to the base mold (3) by means of a screw structure, and the space distance between adjacent columns is three times the thickness of the fiber strips, i.e., 3.6 mm, to ensure that when the single-sector mold (2) is connected to the base mold (3), the adjacent fiber strips are in a close proximity. At this time, the adjacent fiber strips are stitched at a high lattice density, and the stitching density is 2 mm x 2 mm, to ensure the strength of the stitching.

[0022] S5. Cut 36 pieces of fiber cloth.

[0023] Cut 36 pieces of fiber cloth into the shape of Figure 8 The 11th face is composed of two long fan-shaped arcs with a spacing of 0.2, the 12th face is a fan-shaped face with the same size as the fan-shaped face formed by the fiber strips, and the 13th face is composed of two short fan-shaped arcs with a spacing of 0.2. In this embodiment, for the convenience of description, the 12-face fan-shaped face is the same as the fan-shaped face formed by the fiber strips, which may not be the case in practice. The actual 12-face fan-shaped arc is as long as possible to achieve higher fiber continuity.

[0024] The 11th and 13th faces of the cut 36 pieces of fiber cloth are folded downward to form a three-dimensional structure.

[0025] S6. In the single sector mold (2), all the column pieces (1) are pulled out in sequence, and the stitching mold (4) is placed therein, and the disc mold (5) is removed.

[0026] S6. The cut fiber cloth is folded to sequentially cover the vertical surface and the upper curved surface of the strip fiber cloth, and the vertical surface and the strip fiber cloth are sewn together.

[0027] Pull out the column piece in the single fan-shaped mold (2) and insert it into the stitching mold (4). The main part of the stitching mold (4) is used to support the fan-shaped radius of the fan-shaped structure; part of it supports the fan-shaped arc of the fan-shaped structure, and the support part provides stitching space for the stitching process. Remove the disc mold, and according to the shape of the fan, embed the fiber cloth folded by S5 on the top of the fiber strip to perform simple stitching. When stitching the inner circle, flexibly use the disc mold (5) to tighten the fiber structure for stitching. After covering the 6 pieces of three-dimensional fiber cloth, lay a full layer, and then repeat the above steps to lay the second layer. When laying the second layer, because there are breaks between the adjacent fiber cloths in the first layer, the second layer needs to cover the breaks in the first layer. In this way, 6 layers are stacked, and the thickness reaches 1.8mm. The side is stitched with high dot matrix density. The stitching method is hook stitching, and the stitching density is 2mmX2mm to ensure the strength of the stitching.

Claims

1. A hollow annular preform and a method for preparing the same, characterized in that: S1, preparing a complete set of circular ring molds, wherein the circular ring molds include a column sheet (1), a single sector mold (2), a base mold (3), a stitching mold (4), and a disc mold (5); S2, cutting a rectangular fiber cloth, folding it in a wave shape in one direction until the width is equal to the height of the column sheet (1), and simply stitching the folded rectangular fiber cloth; unfolding the fiber cloth at the stitching connection and folding it in a wave shape, stacking the rectangular fiber cloth at the stitching connection according to the wave folding marks, folding it in a wave shape, and then stitching it; S3, the disc mold (5) is embedded in the single sector mold (2), the strip fiber cloth is wrapped around the sector column piece and sewed to connect, and this step is repeated for all single sector molds (2); S4, all the single sector molds (2) are fixed to the base mold (3), a disc mold (5) is placed in the middle, and the rib connection between the sectors is sewn; S5, cutting n pieces of three-arc strip fiber cloth, where n is a positive integer; the three-arc strip fiber cloth is divided into three areas 11, 12, and 13, where area 11 is an arc-shaped long strip, area 12 is a fan-shaped long strip, and area 13 is an arc-shaped short strip; the two sides of the arc-shaped long strip in area 11 are parallel, and the lengths of the two sides of the arc-shaped long strip are equal to the height of the column piece (1), and the arc lengths are equal; the two sides of the arc-shaped short strip in area 13 are parallel, and the lengths of the two sides of the arc-shaped long strip are equal to the height of the column piece (1), and the arc lengths are equal; area 12 is a fan-shaped structure, and the fan-shaped radius is equal to the fan-shaped radius of the rectangular fiber cloth surrounded by the single fan-shaped mold (2), the longer arc side of the fan-shaped is connected to area 11, and the arc length is shared, and the shorter arc side of the fan-shaped is connected to area 13, and the arc length is shared; S6, in the single sector mold (2), all the column pieces (1) are pulled out in sequence, and the pieces are placed into the stitching mold (4), and the disc mold (5) is removed; S7, the cut fiber cloth is folded to cover the vertical surface and the upper circular surface of the whole set of circular ring molds, and the vertical surface is sewed with the strip fiber cloth.

2. A hollow annular preform and a method for preparing the same according to claim 1, characterized in that: The column piece (1) is removable on the fan-shaped mold (2).

3. The hollow annular preform and the preparation method thereof according to claim 1, characterized in that: The thickness of the folded rectangular fiber cloth at the stitching connection is twice.

4. A hollow annular preform and a method for preparing the same according to claim 3, characterized in that: The fibers at the stitching connection are arranged at the rib position, and the size of the fiber cloth at the stitching connection is the same as the size between the two column pieces on one side of the single sector mold (2).

5. The hollow annular preform and the preparation method thereof according to claim 1, characterized in that: The thickness of the rib connection between the sectors is the sum of 1 times the thickness of the strip fiber cloth and 2 times the thickness of the strip fiber cloth, and the thickness of the rib connection is equal to the distance between the column sheets (1) between adjacent sectors.

6. The hollow annular preform and the preparation method thereof according to claim 1, characterized in that: The main part of the stitching mold is used to support the fan-shaped radius of the fan-shaped structure; the support part of the stitching mold supports the fan-shaped arc of the fan-shaped structure, and the support part provides a stitching space for the stitching process.

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