JPH0669728B2 - Method for manufacturing curved preform for composite material - Google Patents

Description

Detailed Description of the Invention [Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a curved-surface preform for a composite material, which is used for manufacturing a curved-surface preform having, for example, a spherical container shape or a curved plate shape. Is. (Prior Art) Generally, a preform of a composite material is manufactured, for example, as one step of manufacturing a fiber reinforced plastic (FRP), and fibers are continuously wound around a jig to form a predetermined shape. A filament winding method and a hand lay-up method in which a woven cloth (or prepreg) is laminated on a jig to form a predetermined shape are well known. Preforms molded by these methods mainly have two-dimensional fiber orientation. Further, as shown in FIG. 14, there is one in which a fiber bundle 100 composed of a plurality of fibers 100a is woven in three orthogonal directions (X, Y, Z directions). When manufacturing a preform with this configuration, for example, between a large number of pins standing in the Z direction,
The fiber bundles 100 in the X and Y directions are woven together, and then the fiber bundles 100 are woven in three directions to form a predetermined shape in such a manner that the pins and the fiber bundles 100 used in the Z direction are exchanged. Such three-dimensional fabrics are produced, for example, by the overseas technical data research institute, “Current situation and problems of research and development of new composite materials.
First Volume / FRP Edition ", page 45 and page 46. (Problems to be Solved by the Invention) However, when a curved surface preform having a spherical container shape, a curved plate shape, or the like is manufactured based on the conventional method as described above, the following will be described. There was a problem. For example, in the case of the filament winding method, it is extremely difficult to form a spherical portion in particular, and there may be a portion where fibers are intensively overlapped, which generally requires a lot of working time. Further, in the case of the hand lay-up method, the work is relatively easy, but due to its structure, the shear strength between the layers formed by the woven fabric is small, and delamination occurs during the subsequent mechanical processing or the like. Sometimes. Further, when a three-dimensional woven fabric manufactured by using pins is applied, the strength is excellent, but a gap is formed between the fiber bundles 100, so that the so-called basis weight becomes rough, and the shape is retained during the compounding process and the like. In particular, it is more difficult for a container or a plate, which has a smaller wall thickness than the entire size, such as a plate or a plate. Therefore, in order to make a container-shaped or plate-shaped product from a three-dimensional woven fabric, the preform is manufactured by making its wall thickness sufficiently large or in a lump shape, and after the compounding treatment or the like, carving out the product. As a result, it is not preferable in terms of material yield. (Object of the Invention) The present invention has been made by paying attention to the above problems in manufacturing a curved surface preform such as a spherical container shape or a curved plate shape. An object of the present invention is to provide a method for producing a curved surface preform for a composite material, which has a good material yield and can obtain a curved surface preform having a three-dimensional fiber orientation.

[Constitution of the invention]

(Means for Solving Problems) A method of manufacturing a curved surface preform for a composite material according to the present invention is a two-dimensional method for manufacturing a curved surface preform having a spherical container shape, a curved fret shape or the like. It is characterized in that a cloth in which the fibers are oriented is laminated on the mother die to form a preform shape, and then the laminated cloth is sewn to obtain a curved surface preform. The fibers used as the material of the preform in the present invention are intended for those used in general fiber-reinforced composite materials, and for example, fibers such as glass, silica, carbon or graphite are used. In addition, as the cloth, a cloth which is used according to the subsequent composite treatment and simply woven of the above fibers, or a cloth which is impregnated with a thermosetting resin (prepreg) is included. Further, the thread used for suturing the laminated cloth is not particularly limited in its material, but for example, the same material as the cloth is preferable, and it is more preferable to use a high-strength fiber having a high flexibility. . (Example) Hereinafter, the present invention will be described with reference to the drawings. 1 to 11 are views for explaining one embodiment of the present invention, in which a curved preform is molded into a nose cap which constitutes a tip portion of a nose fairing for rocket. It is a thing. As shown in FIG. 1, the curved preform P has a substantially constant wall thickness, and is provided with an inward flange portion F continuously over the entire circumference of the edge portion of the spherical surface portion R, so that the overall shape of the container is large. Is done. FIG. 2 is a diagram showing an example of an apparatus used for manufacturing the curved surface preform P. In this apparatus, the curved surface preform P is formed with the opening portion on the flange portion F side facing upward. To manufacture. Reference numeral 1 in the drawing is a stand for holding a basket 11 as a master mold corresponding to the shape of the curved preform P. The stand 1
Is provided with a first arm 4 extending in a substantially horizontal direction and a second arm 5 extending in a substantially vertical direction on the upper end of a column 3 standing upright on the base 2. Both arms 4 and 5 are attached by a wing bolt 6 penetrating the support column 3 and a wing nut (not shown) screwed to the wing bolt 6 so that the angle can be adjusted with respect to the support column 3. . A pad 8 for receiving the top of the spherical portion R of the curved preform P is attached to the tip of the first arm 4 by using a wing bolt 7 and a wing nut (not shown). The pad 8 has a long hole 8a in which the pierce portion of the butterfly bolt 7 is long in the vertical direction, and the position can be adjusted by the length of the long hole 8a. A basket 11 is provided at the tip of the second arm 5.
A ring 9 is fixed for receiving the peripheral portion of the ring 9 and is provided with a plurality of long bolts 10a and nuts 10b used for fixing the basket 11. As shown in FIG. 3, the basket 11 comprises the basket 11a corresponding to the flange portion F and the lower basket 11b corresponding to the spherical surface portion R. As shown in FIG. 4, the upper basket 11a includes a plurality of radially-arranged support members 12 and a first arc-shaped member 13 that individually connects the ends of the support members 12 on the basket center side. Secondly connecting the end portions of the support member 12 on the side opposite to the center individually.
The arcuate member 14 and the auxiliary member 15 for connecting the intermediate portions of the first and second arcuate members 13, 14 between the adjacent support members 12, 12 are provided. The first and second arcuate members 1
3,14 form a concentric array as a whole. Also,
The members 12 to 15 can be attached to and detached from each other. On the other hand, the lower basket 11b includes a plurality of support members 17 arranged radially around the annular member 16, and the support members 17 described above.
A first arc-shaped member 18 for individually connecting the intermediate portions of the above and the end portion of the support member 17 on the side opposite to the center are individually connected 2
An arcuate member 19 and an auxiliary member 20 that connects intermediate portions of the first and second arcuate members 18 and 19 between the adjacent support members 17 and 17 are provided. The annular member 16 and the first and second arcuate members 18, 19 form a concentric arrangement as a whole. Further, the members 16 to 20 can be attached to and detached from each other. The appropriate number of support members 12 and 17 in the upper and lower baskets 11a and 11b are formed with holes 12a and 17a for passing the long bolts 10a at the ends on the side opposite to the center. Next, a process of manufacturing the curved surface preform P using the above apparatus will be described. FIG. 6 is a view for explaining a cut cloth, and the cloth C is, for example, formed by weaving carbon fibers in a vertical and horizontal direction, and integrally has a spherical molding portion r and a flange molding portion f. ing. The spherical molding portion r is provided in the lower basket 11b.
The notches 21 are formed at six locations (not particularly limited) so as to form a spherical shape when housed inside the notches.
The flange forming portion f is continuously provided on the circumferential portion of the substantially fan-shaped portion formed by. Further, since the cloth C is laminated in a spherical shape, several kinds of cloth having different diameters of the spherical molding portion r are used. Note that, as indicated by a virtual line A in the figure, the spherical surface forming portion r may be cut into a radially divided state.
Further, a tape 22 for temporary fixing is attached to the outer peripheral side end of the flange forming portion f. Next, as shown in FIG. 7, the cloth C is laminated inside the lower basket 11b. In this stacking, of course, the cross C having the larger diameter of the spherical surface forming portion r is sequentially performed. At this time, in order to prevent the portions of the cuts 21 from overlapping with each other, as shown by a virtual line B in FIG. It is made to shift sequentially in the circumferential direction of. Also, each time a proper number of layers are laminated, the spherical shaped portion r is temporarily fixed with the thread 23, and finally the spherical shaped portion R is shaped. Next, all the flange forming parts f are folded inward, the upper basket 11a is superposed on the lower basket 11b, and both are fixed by the long bolt 10a and the nut 10b. Further, as shown in FIG. Flange part F with temporary fixing
To mold. The yarns 23 and 24 are made of the same material as the cloth C, for example, and the positions are selected so that the entire laminated state is uniform, and temporary fixing is performed. After this, the flange part F
The edges are cut and aligned, and as shown in FIG. 9, the whole is sewn with a thread 25 of high-strength carbon fiber or the like. Here, FIGS. 10A and 10B are views showing an example of a needle used for suturing. The needle 30 has an elongated threading hole 31 formed near the tip. The threading hole 31 is also open to the side of the needle 30 on the needle base end side, and an inwardly curved hook portion 32 is formed on the needle tip end side of the opening portion. As the usage of the needle 30, the thread 25 is passed through the spherical portion R from one side, the thread 25 is passed through the thread passing hole 31 on the other side, and the thread 25 is pulled out to the one side again to pass the thread 25 through the spherical portion R.
At this time, the opening portion of the threading hole 31 is provided for facilitating the suturing work and dealing with various suturing methods. For example, a part of the thread 25 is pulled out to one side to form a loop. It can also be used for suturing methods such as passing another thread through this loop. Further, since the needle 30 has the curved hook portion 32 in the threading hole 31, it is possible to prevent the opening portion from being caught by the cloth C at the time of pulling out. As shown by the phantom line in FIG. 10 (b), a pipe through which the needle 30 can be inserted.
It is also possible to make the threading work even smoother by using 33 and passing this pipe 33 through the cloth C. In this embodiment, the needle 30 and the two threads 25 described above are used, and
As shown in the drawing, spiral stitching is performed from the center of the spherical surface portion R, stitching is continuously performed up to the flange portion F, and the edge portion of the flange portion F is stitched over the entire circumference to form a curved surface. A preform P is obtained. Further, the above work is performed while sequentially attaching and detaching each member 12 to 20 of the basket 11 at the position corresponding to the sewn portion, or each member 12 to 20 is partially removed to form the curved surface preform P. Do it while rotating. In addition to the spiral shape, the suturing can be performed along a concentric circle, radially, or a combination thereof. The curved preform P thus obtained has a three-dimensional fiber orientation constituted by the laminated cloth C and the thread 25 used for suturing, and has sufficient tensile strength, in-plane shear strength and interlayer shear strength. It is clear to have. Further, the curved preform P is less likely to be deformed due to the above configuration, is easy to handle during the compounding process, and is substantially the same as the final shape after the compounding process. It is also very good in terms of. The curved surface preform P is made into FRP through a resin impregnation and a treatment such as pressurization and heating, and becomes the nose cap described above. Further, the shape of the curved surface preform is not limited to the above-mentioned embodiment, and it can be applied to the curved surface preform P ₁ having a curved plate shape as shown in FIG. 12, for example. This curved surface preform P ₁ has an inward flange portion at the upper end of the curved portion R ₁ where the plate is curved in a substantially U shape.
Have F ₁ . Further, FIG. 13 shows the above preform P ₁
FIG. 14 is a diagram showing an example of a jig as a mother die used for molding, wherein the jig 40 includes three U-shaped supporting members 41, and a plurality of connecting members 42 connecting the supporting members 41, Each support member 41
A pair of flange members 43 that extend the same end portion and extend outward, and a pair of plate members 44 that face the upper surface of the flange member 43 to form the flange portion F ₁ , and each member 41- 44 can be attached to and detached from each other. The curved surface preform P ₁ is molded by using the jig 40 described above in a manner based on the above-described embodiment.

【The invention's effect】

As described above, according to the method for manufacturing a curved surface preform for a composite material of the present invention, when manufacturing a curved surface preform having a spherical container shape, a curved plate shape, or the like, two-dimensionally, After forming a preform shape by laminating a cloth in which the fibers are oriented on the mother die, the laminated cloth is sewn to obtain a curved surface preform, which is difficult to form by a conventional method, that is, Despite the curved shape and the smaller wall thickness compared to the overall size, it is possible to obtain a curved preform having a three-dimensional fiber orientation, which is advantageous in terms of strength. Since it can be molded in accordance with the shape of the product, the yield of the material is good, and it is possible to improve the workability from the manufacturing to the composite treatment.

[Brief description of drawings]

1 is a sectional view for explaining the shape of a curved preform in one embodiment of the present invention, FIG. 2 is a side view for explaining an example of an apparatus used for manufacturing the preform shown in FIG. FIG. 3 is a partial side view illustrating a basket which constitutes the apparatus shown in FIG. 2, FIG. 4 is a partial bottom view of an upper basket, FIG. 5 is a partial plan view of a lower basket, and FIG. 6 is a cross. FIG. 7 is a plan view, FIG. 7 is a cross-sectional view illustrating a state where a spherical surface portion is molded, FIG. 8 is a cross-sectional view illustrating a state where a flange portion is molded, and FIG. 9 is a cross-sectional view illustrating a state where suturing is performed. 10 (a) and (b) are side views for explaining an example of a needle used for suturing, FIG. 11 is a plan view of a spherical surface portion for explaining the procedure for suturing, and FIG. 12 is another curved surface preform. Fig. 13 is a perspective view illustrating a shape example, and Fig. 13 shows the curved preform shown in Fig. 12. FIG. 14 is a perspective view illustrating a jig used for shaping, and FIG. 14 is a perspective view illustrating a conventional three-dimensional fabric. P, P ₁ …… Curved surface preform, C …… Cross, 11 …… Basket (mother mold), 40 …… Jig (mother mold).

Claims (1)

[Claims] 1. When manufacturing a curved surface preform having a spherical container shape, a curved plate shape or the like, a cloth in which fibers are two-dimensionally oriented is laminated on a mother die to form a preform shape. Then, the laminated cloth is sewn to obtain a curved surface preform, which is a method for manufacturing a curved surface preform for a composite material.