JP4656564B2 - Manufacturing method of three-dimensional fiber structure - Google Patents

Description

  The present invention relates to a method for producing a three-dimensional fiber structure used for a composite material containing reinforcing fibers.

Conventionally, this type of three-dimensional fiber structure has been disclosed in, for example, Japanese Patent Publication No. 62-3258. The structure described in the publication is a cylindrical reinforcing structure formed by tertiary knitting of three linear objects, and in order to manufacture this structure, the axis is set to the vertical direction. After arranging a large number of metal bars in parallel with each other at a predetermined interval, horizontal linear objects are knitted between these metal bars, and the same linear objects are stacked in a vertical direction, and then perpendicular to the metal bars. I tried to replace the linear objects in the direction.
Japanese Patent Publication No.62-3258

  However, in the conventional method for producing a three-dimensional fiber structure as described above, since a large number of metal rods and linear objects are replaced, the work takes a great deal of labor and time, and the structure There is a problem that the replacement work becomes more difficult as the vertical dimension increases, and an improvement in simplification of manufacturing has been demanded. Further, in the conventional manufacturing method, since a large load is easily applied to the linear object at the time of insertion in the axial direction, there is a problem that it is difficult to employ a highly elastic fiber as the linear object.

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a method for manufacturing a three-dimensional fiber structure capable of realizing a reduction in man-hours, a reduction in manufacturing time, and a reduction in cost. It is said.

  The manufacturing method of the three-dimensional fiber structure according to the present invention is as described in claim 1, in manufacturing a three-dimensional fiber structure in which fibers are three-dimensionally oriented, the fibers are made into rods with resin. A large number of molded bars are arranged in parallel with each other at a predetermined interval to form a Z-direction fiber group, and then continuous fibers are knitted along the XY plane orthogonal to the Z-direction fiber group. It is set as the structure which laminates | stacks a fiber in a Z direction, and it has become the means for solving the conventional subject with the said structure.

  In the method for producing a three-dimensional fiber structure according to the present invention, as described in claim 2, the structure has a cylindrical shape whose axial direction is the Z direction, and is substantially cylindrical by a large number of rods. A Z-direction fiber group forming a shape is formed, and continuous fibers are knitted in the circumferential direction and the radial direction along the XY plane with respect to the fiber group, and the fiber group according to claim 3. The plurality of bars have a cross-sectional shape selected from a circular cross-section and a square cross-section, and the bar may further include fibers and In addition to the resin, at least one of pitch and carbon black is included.

  According to the method for manufacturing a three-dimensional fiber structure according to claim 1 of the present invention, since a group of fibers in the Z direction composed of a large number of rods in which fibers are molded into a rod shape using a resin is used, continuous fibers along the XY plane are used. Since the fiber group used for knitting becomes the fibers in the Z direction as they are, the structure having a large dimension in the Z direction can be easily manufactured. Since a large load is not applied in the axial direction to the Z-direction fiber group, highly elastic fibers can be employed in the Z-direction, and the conventional metal rod removal work is not required. Reduction of man-hours, shortening of manufacturing time, and cost reduction associated therewith can be realized.

  In addition, since the conventional manufacturing method requires replacement of the metal rod and the Z-direction linear object, there is a certain limit to the amount of X- and Y-direction fibers that can be set. However, according to the manufacturing method of the present invention, even a structure having a large dimension in the Z direction can be easily manufactured, so that the input amount of fibers in the X and Y directions may be limited. In addition, the limit of the density of the fiber as in the conventional case can be eliminated.

  In addition, the three-dimensional fiber structure obtained by the method for producing a three-dimensional fiber structure according to the present invention becomes a fiber-reinforced plastic material (FRP material) through resin impregnation and curing treatment later, particularly when carbon fiber is used. Is a carbon / carbon composite material (C / C material) that is subjected to a composite treatment such as repeated impregnation and firing of pitch, and is used as a preform for these materials. This can contribute to time reduction and cost reduction in manufacturing.

  According to the method for manufacturing a three-dimensional fiber structure according to claim 2 of the present invention, the manufacturing time can be shortened and the cost can be reduced in the manufacture of the cylindrical structure. Such a cylindrical structure can be used, for example, as a preform for a rocket nozzle material, and in this case, can contribute to shortening of time and cost reduction in the manufacture of rocket nozzles.

  According to the method for manufacturing a three-dimensional fiber structure according to claim 3 of the present invention, the cross-sectional shape of the bar material in the Z direction is selected from a circle and a square according to the shape of the target three-dimensional structure. By selecting, the input amount of the fiber can be adjusted by changing the size of the gap between the bar and the fiber in the X and Y directions.

  According to the method for producing a three-dimensional fiber structure according to claim 4 of the present invention, by using a bar material containing at least one of pitch and carbon black in addition to fibers and resin, a subsequent compounding treatment can be performed. Easy and reliable. That is, when a three-dimensional structure is made of, for example, a carbon / carbon composite material, even if the structure is large, the entire structure can contain pitch and carbon black uniformly. In the treatment, it is possible to simplify the work of impregnating the structure with pitch or carbon black, and it is possible to promote overall densification during firing.

  Hereinafter, an embodiment of a method for producing a three-dimensional fiber structure according to the present invention will be described with reference to the drawings.

  A three-dimensional fiber structure (hereinafter referred to as “structure”) A shown in FIG. 2 has a cylindrical shape and three-dimensionally oriented fibers, and the fiber F1 is formed into a rod shape with a resin. A Z-direction (axial direction L) fiber group composed of a large number of rods B, and continuous fibers knitted along an XY plane orthogonal to the fiber group and laminated in the Z direction, that is, radial direction R and circumferential direction C continuous fibers F2 and F3 are provided. Each bar B is obtained by, for example, molding a bundle of carbon fibers into a bar shape with a thermosetting resin in advance. Moreover, each continuous fiber F2, F3 may be a bundle of fibers only, or may be a fiber bundle impregnated with a resin.

  Here, examples of the bar B include those having a circular cross section as shown in FIG. 3 (a) and those having a square cross section as shown in FIG. 3 (b). The bar B is selected from a circular cross-section and a square cross-section according to the shape of the target structure A and the like, and thereby the gap between the bar B and the continuous fibers F2 and F3 in the X and Y directions. The size of will be different. If the cross-sectional circle shown in FIG. 3 (a) is selected, gaps S are formed on the four sides of the bar B on the plane. If the cross-sectional square shown in FIG. 3 (b) is selected, there is no gap on the plane. It will be a thing.

  That is, by selecting the cross-sectional shape of the bar B, it is possible to change the size of the gap and adjust the input amount of the entire fiber. In addition, all the rods B may have the same cross-sectional shape, or may have different cross-sectional shapes depending on the position in the fiber group. Further, the bar B may have an oval cross section in addition to a circular cross section, and the cross section square naturally includes a square other than the illustrated square.

  Furthermore, the bar B may include at least one of pitch and carbon black in addition to the fibers F1 and the resin in the Z direction in response to the subsequent composite treatment.

  The forming apparatus for the structure A includes, for example, a substrate that is driven to rotate about a vertical axis, and a guide plate that can move up and down on the upper side of the substrate, and fixes the lower end of each bar B to the substrate, Each bar B is passed through the guide plate. At this time, the rods B are maintained in a positional relationship with each other by the guide plate, and are arranged parallel to each other with the axes perpendicular to each other, corresponding to the cylindrical shape formed by the structure A, and in the radial direction and the circumferential direction. As shown in FIG. 1, the fiber group FF having a substantially cylindrical shape is regularly arranged in the direction. FIG. 1 schematically shows the arrangement and the like of the rods B. In practice, the rods B are arranged more densely.

  Further, the molding apparatus includes a first nozzle NZ1 that supplies continuous fibers F2 in the radial direction R to the fiber group FF in the Z direction (L direction) at a position corresponding to the ascent limit of the guide plate, and a circumferential direction C. The second nozzle NZ2 for supplying the continuous fibers F3 and a plurality (four in the illustrated case) of pressing jigs P for pressing the continuous fibers F2 and F3 downward.

  The first nozzle NZ1 continuously supplies one continuous fiber F2 from a fiber supply source (not shown), and the radial direction of the fiber group FF is between the outer peripheral side and the inner peripheral side of the fiber group FF. Reciprocate. The second nozzle NZ2 continuously supplies a plurality of continuous fibers F3 from a fiber supply source (not shown), and includes a plurality of supply sections corresponding to the bars B in the radial direction. Further, the press jig P has a wedge shape extending in the radial direction with respect to the fiber group FF, pressurizes the continuous fibers F2 and F3 knitted by the descending operation, and upwards the fiber group FF or a predetermined direction. The fiber group FF can be retracted from the ascending position.

  In order to manufacture the structure A using the above molding apparatus, the fiber group FF is set and the guide plate is moved to the ascending limit, and then the fiber group FF is rotated while rotating the fiber group FF in the radial direction R and the circumferential direction C. Knit continuous fibers F2 and F3.

  That is, the first nozzle NZ1 is moved forward from the outer peripheral side to the inner peripheral side, the continuous fibers F2 in the radial direction R are supplied between the rows of the rods B, and subsequently, the fiber group FF is moved to each rod row. After rotating by one pitch, the first nozzle NZ1 is moved back from the inner peripheral side to the outer peripheral side to supply continuous fibers F2 between adjacent rows. At this time, the continuous fiber F2 in the radial direction R is led out from the nozzle NZ1 together with the movement of the first nozzle NZ1 by fixing the start end to the fiber group FF in advance. Thereafter, the rotation of the fiber group FF and the reciprocation of the first nozzle NZ1 are repeatedly performed, and the continuous fiber F2 in the radial direction R is knitted on the fiber group FF. The rotation of the fiber group FF may be either continuous or intermittent.

  Further, on the upper side of the continuous fibers F2 in the radial direction R, the continuous fibers F3 in the circumferential direction C are supplied between the rows of the bars B from the supply units of the second nozzle NZ2. At this time, the continuous fiber F3 is led out from the second nozzle NZ2 together with the rotation of the fiber group FF by fixing the start end to the fiber group FF in advance. Thus, by supplying the continuous fibers F2 in the radial direction R and the continuous fibers F3 in the circumferential direction C with the rotation of the fiber group FF, these continuous fibers F2 and F3 are alternately arranged in the axial direction L (Z direction). It will be laminated.

  Further, the molding apparatus intermittently drives the press jig P as the continuous fibers F2 and F3 are stacked, and pressurizes the continuous fibers F2 and F3 between the press jig P and the guide plate. Since the supply position of the continuous fibers F2 and F3 is constant, the guide plate is lowered continuously or intermittently. That is, by repeating the lamination of the continuous fibers F2 and F3 and the pressurization by the press jig P with the rotation of the fiber group FF described above, the guide plate is lowered as the lamination height increases. Finally, a structure A having a predetermined height in which the fibers F1 to F3 are three-dimensionally oriented is completed.

  According to the manufacturing method of the structure A described above, the Z-direction fiber group FF composed of a large number of rods B in which the fibers F1 are formed into a rod shape with resin is adopted, and the upper part of the fiber group FF becomes an open end. Therefore, it is easy to automate when knitting continuous fibers along the XY plane, that is, continuous fibers F2 and F3 in the radial direction R and the circumferential direction C.

  Further, since the fiber group FF used for knitting is the fiber F1 in the Z direction as it is, it is not affected by the dimension in the Z direction, and even the structure A having a large dimension in the Z direction can be easily manufactured. In addition, since a large load is not applied in the axial direction to the Z-direction fiber group FF, highly elastic fibers can be employed in the Z direction. And since the conventional removal work of the metal rod is not necessary, the man-hour can be greatly reduced compared with the conventional case, and the manufacturing time can be shortened. it can.

  Furthermore, the structure A of the above embodiment has a cylindrical shape and uses carbon fiber, and is used as a preform for a rocket nozzle material, for example. That is, the structure A is, for example, made into FRP through resin impregnation and curing treatment, and becomes a carbon / carbon composite material (C / C material) through a composite treatment in which firing and pitch impregnation are repeated. By machining, it becomes a rocket nozzle. For this reason, the said manufacturing method can also contribute to shortening of the manufacturing time and cost reduction of a rocket nozzle.

  Here, when performing the composite treatment as described above, as described above, in addition to the fibers F1 in the Z direction and the resin, if the bar B containing at least one of pitch and carbon black is used, the composite treatment is performed. Processing is easy and reliable.

  That is, in the composite treatment, the structure A is impregnated with pitch or carbon black. At this time, the larger the structure A is, the more difficult it is for the pitch and carbon black to reach the inside. Therefore, if the structure A is formed by using the bar B containing pitch and carbon black, even if the structure A is large, the pitch and carbon black are uniformly distributed throughout. In the composite treatment, the work of impregnating the structure A with pitch or carbon black is simplified, and overall densification is promoted during firing, so that a high-quality composite material can be obtained.

  In addition, as for the manufacturing method of the three-dimensional fiber structure which concerns on this invention, a detailed structure is not limited only to the said Example, For example, it can also be set as various shapes other than a cylindrical shape, The fiber to be used Even in the case of resin or resin, it can be appropriately selected according to the purpose of use.

It is a top view explaining one Example of the manufacturing method of the three-dimensional fiber structure concerning this invention. It is a perspective view explaining a three-dimensional fiber structure. It is a top view (a) which shows a cross-section rod and a continuous fiber, and a top view (b) which shows a square cross-section rod and a continuous fiber.

Explanation of symbols

A Three-dimensional fiber structure B Bar material F1 Fiber in the axial direction L (Z direction) F2 Continuous fiber in the radial direction R F3 Continuous fiber in the circumferential direction C FF fiber group

Claims (4)

  When manufacturing a three-dimensional fiber structure in which the fibers are three-dimensionally oriented, a large number of rods obtained by molding the fibers into a rod shape with a resin are arranged in parallel with each other at a predetermined interval to form a Z-direction fiber group. Then, the continuous fiber is knitted along the XY plane orthogonal to the fiber group in the Z direction, and the continuous fiber is laminated in the Z direction.   The structure has a cylindrical shape whose axial direction is the Z direction, and a Z-direction fiber group is formed by a large number of rods to form a substantially cylindrical shape, and continuous fibers are arranged in the circumferential direction and the radial direction with respect to this fiber group. The method for producing a three-dimensional fiber structure according to claim 1, wherein knitting is performed.   The method for producing a three-dimensional fiber structure according to claim 1 or 2, wherein the plurality of rods have a cross-sectional shape selected from a circular cross-section and a square cross-section.   The method for producing a three-dimensional fiber structure according to any one of claims 1 to 3, wherein the bar material includes at least one of pitch and carbon black in addition to the fiber and the resin.

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