Weaving method of special-shaped structure

Abstract

The invention discloses a weaving method of a special-shaped structure, which is characterized in that parts with different sectional areas of a prefabricated part of the special-shaped structure are decomposed, a three-dimensional weaving machine corresponding to the parts with different sectional areas in quantity is adopted, and yarn hanging operation is carried out according to different sectional dimensions; the knitting machines at the adjacent stations are interwoven through yarn replacement in each cycle in the knitting process, yarn increasing and decreasing operation does not need to be carried out, bending, broken filaments and breakage of the yarn or formation of sparsity and holes in the structure are avoided, finally, the special-shaped structure prefabricated body is integrally knitted, the size is accurate, and the structure is stable.

Description

Technical Field

[0001] The invention belongs to the technical field of weaving, and in particular relates to a weaving method for a special-shaped structural prefabricated part. Background Art

[0002] Three-dimensional weaving technology is an important weaving process for making composite preforms. This technology forms an integral component by interweaving and orienting yarns in multiple directions in the preform. It can realize the molding of special-shaped parts of various shapes and sizes, overcome the problem that traditional composite materials are easy to delaminate after being subjected to force, and avoid mechanical processing of subsequently manufactured composite parts. Therefore, the use of this weaving technology can form composite materials with diverse structures and good performance.

[0003] When a row-column structure braiding machine is used for three-dimensional braiding, the yarn carriers are moved cyclically along the rows and columns on the machine chassis, and the yarns are interwoven to form preforms. During the braiding process, the size of the yarn array does not change, and it is difficult to achieve the braiding of variable-section preforms by moving the entire row and column of the yarn carriers. In addition to using the yarn increase and decrease technology of three-dimensional braiding, the present invention provides a method for achieving preforms with special cross-sections by using a multi-station braiding machine. Summary of the invention

[0004] The present invention provides a knitting method for a special-shaped structure, which analyzes the structure of the special-shaped cross-section, decomposes the parts with different cross-sectional areas, and performs yarn hanging operations according to the cross-sectional sizes. During the knitting process, the knitting machines at adjacent stations are interlaced by changing the yarns, without the need to increase or decrease the yarns. To achieve the above purpose, the present invention is implemented through the following technical solutions: A knitting method for a special-shaped structure, comprising the following steps:

[0005] (1) Decompose the target special-shaped structural parts according to different cross-sections, prepare three-dimensional braiding machines required for braiding and forming according to the number of different cross-sections decomposed, and arrange them in parallel;

[0006] (2) Calculate the number of yarns according to the fiber volume fraction requirements, tow size, and cross-sectional dimensions of the special-shaped structural parts, and perform yarn hanging;

[0007] (3) A three-dimensional multi-directional weaving method is used for weaving. When the yarn carrier moves along the rows and columns to complete a cycle, the yarn is changed between the multi-station weaving machines to perform axial tightening.

[0008] (4) Repeat the three-dimensional multi-directional weaving operation until the target size is reached, and then perform gluing treatment to finally form a preform.

[0009] The cross-sectional dimensions of the special-shaped structural prefabricated part vary discontinuously along the length direction.

[0010] The advantages of the present invention are as follows: the method is used to weave a special-shaped structure formed in one piece, and the weaving process uses multiple weaving machines to hang yarns according to different cross-sections of the special-shaped structure. The number of yarns in the weaving array and the weaving process are constant, and the pattern is uniform and the structure is stable after forming. It avoids the disadvantages of using the yarn increase and reduction technology to separate and cut the yarns, causing the yarns to bend, fluff and break, or the reduction of the yarns to form a sparse and porous structure, which leads to a reduction in the mechanical properties of the preform, and the difficulty in achieving fine-fine cutting in actual operation, and the difficulty in accurately controlling the external dimensions. DETAILED DESCRIPTION

[0011] The specific implementation of the present invention is described in detail below: Using 1K continuous silicon carbide fiber as raw material, a preform with a concave structure is woven:

[0012] (1) Divide the concave structure into three sections according to the cross-sectional size and prepare three row-column structure braiding machines;

[0013] (2) The raw material is continuous silicon carbide fiber (1K). According to the size of the concave structure (width 150 mm) and the fiber volume content (45%), the raw material requirements are calculated, and the weaving process in Table 1 is used for hanging yarn;

[0014] Table 1 Weaving process table

[0015]

[0016] (3) After the wire hanging is completed, the three-dimensional four-way 1*1 method is used to pick up the yarn for weaving. The yarn is changed from the first cycle and tightened axially. The yarn bundles between adjacent weaving machines are cross-connected as a whole through the yarn changing process to ensure that the preform is not layered and is tightly connected.

[0017] (4) Repeat the above steps until the preform is knitted to the target size.

[0018] The present invention is disclosed above only in terms of preferred embodiments, which are not intended to limit the present invention. Any technical solutions obtained by equivalent replacement or equivalent transformation shall fall within the protection scope of the present invention.

Claims

1. A method for weaving a special-shaped structure, It is characterized in that The following steps are involved: (1) Decompose the special-shaped structural prefabricated parts according to the parts with different cross-sectional areas, and prepare a corresponding number of three-dimensional braiding machines according to the number of parts with different cross-sectional areas, and arrange them in parallel; (2) Calculate the number of yarns according to the fiber volume fraction requirements of the special-shaped structural parts, the size of the yarn tows, and the cross-sectional dimensions of each department, and perform yarn hanging; (3) A three-dimensional multi-directional weaving method is used for weaving. When the yarn carrier moves along the rows and columns to complete a cycle, the yarn is changed between the multi-station weaving machines to perform axial tightening; (4) Repeat the three-dimensional multi-directional weaving operation until the target size is reached, and then perform gluing treatment to finally form a preform.

2. A method for weaving a special-shaped structure according to claim 1, It is characterized in that The cross-sectional dimensions of the special-shaped structural prefabricated part vary discontinuously along the length direction.

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