JPH0151586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fibrous structure for reinforcing composite materials, and more specifically, a fibrous structure with shape retention in which substantially no cut ends of threads are present on the end face of the fibrous structure. The present invention relates to a fiber structure for reinforcing composite materials that has good properties and a high yarn lamination density.

Prior Art Three-dimensional fabrics such as glass fiber fabrics and carbon fiber fabrics are used as structural members of mechanical devices that require strength such as spacecraft, aircraft, automobiles, railway vehicles, and ships, or as structural members of buildings. A composite material of synthetic resin reinforced with a fibrous structure is used. Furthermore, composite materials made of combinations of carbon fiber/carbon matrix, graphite fiber/carbon matrix, graphite fiber/graphite matrix, etc. are used as molding materials for structural members that are required to have heat resistance of 1000° C. or higher.

Composite molded products reinforced with such fiber structures are lightweight and at the same time have extremely high strength and flexibility, and are used not only in the above application fields but also in various industrial fields. Its usefulness has been evaluated. Therefore, the strength properties of such composite molded products (for example, FRP and C-C composites) are determined by the fiber content, fiber arrangement, texture, or It is greatly affected by the structure etc. As means for manufacturing these fiber structures, for example, US Pat. No. 4,183,232,
French Patent No. 2440494, Japanese Patent Application Laid-Open No. 59-71457, etc. are disclosed.

Problems to be Solved by the Invention However, the fiber structure described in the above-mentioned U.S. patent has drawbacks in that its dimensions are restricted and the cut ends of the yarns are exposed in the direction perpendicular to the fiber lamination surface. Furthermore, the fiber structure described in the French patent has the drawbacks of dimensional limitations and exposure of the cut ends of the threads in the radial direction relative to the fiber lamination surface. Moreover, JP-A-59-
The fibrous structure described in Japanese Patent No. 71457 also suffers from the same problem of size restrictions. In addition, all of these known fiber structures for reinforcing composite materials have a low content ratio of reinforcing fibers, so it is difficult to maintain the necessary strength. The ends of the yarn are cut and exposed, so when impregnated with thermosetting resin, thermoplastic resin, pitch, etc., the yarn may fall off and cause the fiber structure to lose its shape, or the portion where the shape loss occurs. In order to remove this part, it is necessary to cut the part after the resin, pitch, etc. have hardened. Additionally, machining is essential when manufacturing a composite molded product having a complex shape, which also causes the problem of reduced strength.

The main object of the present invention is to provide a fiber structure for reinforcing composite materials that can solve the above-mentioned problems observed in fiber structures used as reinforcing materials for conventional composite molded products. be.

Another main object of the present invention is to provide a composite molded product reinforced with fiber material with a unique structural feature in which the ends of the fiber threads constituting the base material are not exposed on the outer and inner surfaces. The object of the present invention is to provide a fibrous structure that has a unique structure.

Means for Solving the Problems In view of the above object, the present invention maintains a predetermined arrangement direction (for example, the axial direction of a cylindrical fiber structure, X) of yarns over one or more layers. After being arranged in a meandering manner, the laminated layers are arranged in a winding manner under tension in a second arrangement direction (for example, the circumferential direction of the cylindrical fiber structure, Y) different from the first arrangement direction (X-axis direction). , a first endless yarn 1 that applies a tightening force, and a third endless yarn that penetrates the stack of the first endless yarn 1.
a second endless yarn 2 arranged meanderingly in the arrangement direction (for example, the radial direction of the cylindrical fiber structure, Z);
A third endless yarn 3 is inserted as a cannula thread into the loop 2' of the second endless yarn 2 formed on the surface of the stack of the first endless yarn 1, and
The gist of the present invention is a fiber structure for reinforcing a composite material, in which a stack of endless threads 1 is tightened by the second endless thread 2 and the third endless thread 3 to improve the stacking density of the endless threads. It is something.

Embodiment FIG. 1 is a partially cutaway perspective view illustrating a case where a fiber structure for reinforcing a composite material has a hollow cylindrical shape, and FIG. 2 is a cross-sectional view thereof.

In this embodiment, the first endless yarn 1 forming the fiber structure is arranged in a meandering manner in one layer in the axial direction (X-axis direction) of the fiber structure having a hollow cylindrical shape.
Next, the phase is shifted in the circumferential direction Y and the yarns are further arranged in a meandering manner to form an arrangement layer of yarns, and then the arrangement direction is changed so that the arrangement direction is approximately perpendicular to the axial direction (X-axis direction) of the fiber structure. A predetermined tightening force is applied to the arrayed layer of threads arranged in a winding manner under tension in the circumferential direction Y of the fiber structure and meanderingly arranged in the X-axis direction. The number of repetitions of the combination of the meandering arrangement and the winding arrangement of the first endless yarn 1 along the X-axis direction and the Y direction is determined so as to match the design dimensions of the finally obtained fiber structure. . The second endless yarn 2 extends in the third direction through the stack of first endless yarns 1 formed by repeating the meandering arrangement and the winding arrangement. For example, in this embodiment, the second endless yarn 2 is arranged in a meandering manner in the radial direction (Z-axis direction) of the fiber structure. Furthermore, as shown in FIG. 1, the loops 2' of the second endless yarns 2 formed on the surface of the stack of the first endless yarns 1 by the meandering arrangement in the Z-axis direction are coated with cannula threads. 3
An endless thread 3 is inserted through the thread. In this way, the stack of the first endless yarn 1 is firmly tightened by the second endless yarn 2 and the third endless yarn 3,
A fiber structure for reinforcing composite materials with improved lamination density is formed.

These fibrous structures can be finished into final products as they are, or after being impregnated with a thermosetting resin, thermoplastic resin, pitch, or the like according to a conventional method.

Although the above examples illustrate specific embodiments of the present invention in the case where the fiber structure is a hollow cylindrical body, the gist of the present invention should not be construed as limited by such illustrative explanations. For example, as shown in FIG. 3, fiber structures such as a truncated cone shape, a cone cave shape, or a spindle shape are also included. Further, in the above embodiment, substantially one endless yarn 1 repeats the meandering arrangement and the winding arrangement to form a laminate, but as long as no cut ends are formed on the surface of the fiber structure. It is also possible to form a fiber structure by joining two or more first endless threads during the formation of the laminate depending on the shape and dimensions of the fiber structure. Furthermore, the thickness of the endless yarns 1, 2, and 3 and the type of yarn-constituting fibers can be changed depending on the strength characteristics required of the fiber structure.

As the endless yarn in the present invention, for example, drawn yarn or twisted yarn such as carbon fiber, silicon carbide fiber, graphite fiber, glass fiber, metal fiber, polyamide fiber, or polyester fiber is used.

Effects of the Invention The fiber structure according to the present invention has a high yarn lamination density and a strong tightening structure, so the morphological stability of the final product is remarkable compared to conventional fiber structures. improve. Furthermore, in the present invention, the arrangement direction of the yarns, the number of yarns used, and the lamination density can be changed as appropriate depending on the shape and dimensions of the fiber structure, or the required strength. Can be easily adapted. In addition, since the fiber structure according to the present invention has substantially no cut ends of the threads exposed on its surface, the threads may fall off during transportation or during the resin impregnation process, causing the fiber structure to lose its shape. There is no risk of this occurring, and there is no need to cut the part after the resin or pitch has hardened to correct the shape. Therefore, the fibrous structure according to the present invention can not only be easily adapted to molding composite materials having complicated shapes, but also can greatly contribute to preventing strength reduction due to machining. .

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view illustrating a case where the fiber structure for reinforcing a composite material has a hollow cylindrical shape, and FIG. 2 is a partially cutaway perspective view of the fiber structure along line A-A in FIG. FIG. Moreover, FIG. 3 is a perspective view illustrating a fiber structure according to the present invention. 1...First endless yarn, 2...Second endless yarn, 3...Third endless yarn, 2'...Loop of second endless yarn.

Claims (1)

[Claims] 1. After one or more layers of yarn are arranged in a meandering manner while maintaining a predetermined arrangement direction, the threads are wound and arranged under tension in a second arrangement direction different from the first arrangement direction, and the a first endless yarn that applies a tightening force to the lamination; a second endless yarn that passes through the lamination of the first endless yarn and is arranged in a meandering manner in a third arrangement direction; A third endless yarn is inserted as a cannula yarn into a loop of the second endless yarn formed on the surface of the stack of endless yarns, and the first endless yarn stack is connected to the second endless yarn loop. Thread and third
A fiber structure for reinforcing composite materials, which is tightened with endless threads to improve the lamination density of the endless threads.