JP4991109B2 - Preform manufacturing method, fiber base material used in the manufacturing method, and preform manufacturing apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing a preform that is an intermediate product of a fiber-reinforced composite material, and relates to a method for manufacturing a preform that shapes a fiber substrate using a shaping mold.

  In the case of forming a fiber base material using a shaping mold, a technique is known in which the fiber base material is pressed in order from a high convex shape. Regarding this type of molding technique, the first patent document describes a technique in which a fluid jig is pressed against a fiber base material from a highly undulating position.

However, since this fluidity jig cannot enter the corners of the shaping mold, bridging (a state in which the fiber material is stretched and does not adhere to the shaping mold) occurs in a complicated shape portion. was there. In addition, there is a problem that in a complicated shape portion, the forming speed of the fluidity jig is slow and the productivity is low.
JP 2001-269987 A

The present invention has been made in view of the above problems, and an object thereof is to suppress the occurrence of problems such as bridging and improve production efficiency.
According to the present invention, there is provided a method for manufacturing a preform that presses a substantially center of a fiber base set in a shaping mold and then presses the fiber base toward a direction away from a substantially center of the fiber base toward the end. Provided.

  According to the preform manufacturing method of the present invention, a high-strength preform can be manufactured with high production efficiency without causing bridging, misalignment, wrinkles and the like.

<First Embodiment>
Hereinafter, based on FIGS. 1-7, the preform manufacturing method of 1st Embodiment which concerns on this invention is demonstrated. The preform manufacturing method of this embodiment is a method of shaping a fiber substrate into a predetermined three-dimensional shape using a shaping mold. In this preform manufacturing method, a shaping mold for forming a predetermined three-dimensional shape is first prepared, a fiber base material is set in the prepared shaping mold, and the shaping mold is clamped in a state where the fiber base material is set. The fiber substrate is shaped into a predetermined three-dimensional shape.

  First, a fiber base material is prepared. As the reinforcing fibers, inorganic fibers such as glass fibers and carbon fibers, and organic fibers such as aramid fibers and polyethylene fibers can be used. In the present embodiment, fabric-like continuous fibers such as woven fabric, knitted fabric (knitted fabric), nonwoven fabric, and mat are used. It is preferable to add a binder having a fiber converging function including a thermosetting resin, a thermoplastic resin, or a polymer from the viewpoint of preventing fuzz and improving the shape stability of the fiber base material.

  A shaping mold is prepared in parallel with the preparation of the fiber base material. The shaping mold used in this embodiment has a pair of male and female upper and lower molds that are relatively accessible, and the upper mold and the lower mold approach each other with the fiber substrate sandwiched between them. By tightening, the fiber base material is formed into a desired shape. From the viewpoint of facilitating the release of the shaped fiber substrate, a silicon-based release material may be applied to the shaping surface of the shaping mold, or the shaping surface may be covered with a silicon film or a polyethylene film. May be.

  The prepared fiber base material is set in the prepared shaping mold, and the fiber base material is pressed toward the shaping mold so that the fiber base material adheres closely to the shaping mold. The preform manufacturing method of the present embodiment is characterized in how to hold the fiber substrate. A method of pressing the fiber base material in this embodiment will be described with reference to FIG.

  In the manufacturing method of this embodiment, first, the center part set to the approximate center of the fiber base material set to the shaping mold is pressed. Although not particularly limited, it is preferable that the substantially central portion P0 is the geometric center of the fiber base material. The calculation method of the geometric center is not particularly limited, and a general method can be used. In addition, when the shape of a fiber base material is complicated, you may consider a fiber base material as a simple figure and may obtain | require a geometric center.

  In the manufacturing method of this embodiment, after pressing the center part of a fiber base material, a fiber base material is pressed in order toward the direction spaced apart from the approximate center of a fiber base material to an edge part. The fiber base material may be continuously pressed so as to be stroked, or previously set positions may be sequentially pressed.

  When the fiber base material is continuously pressed, as shown in FIG. 1, the central portion P0 (pressing portion S1) set in the substantially central P1 region of the fiber base material 1 initially set in the shaping mold is used. Hold down. Next, the fiber base material is continuously pressed from P0 in the directions of the arrow R and the arrow L, and is then applied to the shaping mold.

  In addition, you may make it hold | suppress the 1 or 2 or more part preset in the arbitrary positions separated toward the edge part from the approximate center of the set fiber base material in order separated from the center part. Specifically, as shown in FIG. 1, first, the center portion P0 (pressing portion S1) set in the substantially central P1 region of the fiber base 1 set in the shaping mold is pressed. Next, the pressing portions S21, S22, S31, and S32 set in advance in the region P2 and the region P3 at arbitrary positions separated from the substantially center P1 region of the fiber base toward the end of the fiber material are arranged in the center portion. Hold in order of separation from P0. That is, the pressing is performed in the order of S1, S21, S22, S31, and S32. If the distance from P0 of S21 and S22 is substantially the same, the order of S21 and S22 may be switched. The same applies to S31 and S32. If the distances from P0 to S1, S21, S22, S31, and S32 are L1, L21, L22, L31, and L32, L1 <(L21, L22) <(L31, L32) and the fiber substrate is pressed. The order is ascending in the direction away from the approximate center of the fiber base toward the end. In other words, after pressing the end of the fiber base (the distance from the center is T1), the vicinity of the center of the fiber base (the distance from the center is T2 (T2 <T1)) is not pressed.

  Here, for the sake of brevity, the degree of separation from the center is indicated by a concentric circle, and five pressing portions are set on the X axis passing through the center, but the positions, number, spacing, and directions of the pressing portions are limited. Not. The pressing portion may be set in a radial shape from the center, or may be set in a spiral shape from the stop to the end portion.

  Further, when the position to be pressed is set in advance, it is preferable to set the position to a position that is different in height from the position pressed before (there is a level difference from the position pressed before). Moreover, when the uneven | corrugated shape is formed in the shaping type | mold, it is preferable to set a pressing part in the corner | angular part or corner part formed in the trough part of the uneven | corrugated shape.

  The procedure for pressing the fiber substrate 1 against the shaping mold 2 is shown in FIG. S1, S21, S22, S31, and S32 shown in FIG. 2 correspond to those in FIG. FIG. 2A shows a state in which the fiber base 1 is set in the shaping mold 2. FIG. 2B shows a state in which the pressing portion S1 at the substantially center of the fiber base material 1 is pressed following the state of FIG. FIG. 2C shows a state where the pressing portions S21 and S22 are pressed. Further, FIG. 2D shows a state where the pressing portions S31 and S32 are pressed. Here, the method of sequentially pressing S1, S21, S22, S31, and S32 has been described, but it may be pressed so as to continuously boil from S1 through S21 to S31. The same applies to S32 through S1 to S22.

  In this way, by successively pressing the portions that are continuous or set along the direction from the approximate center to the end of the fiber base material, it is possible to suppress the occurrence of wrinkles and misalignment, and partial A stable quality preform with no difference in strength can be obtained.

  In the state of FIG. 2 (A), a plurality of fiber base materials may be stacked and set in a shaping mold. This state is shown in FIG. In the present embodiment, as shown in FIG. 3, three fiber base materials 11, 12, and 13 are stacked and set on the shaping mold 2. If fiber base materials are set one by one in sequence, misalignment and wrinkles may occur due to the force from the upper base material on which the lower base material is laminated, but multiple fiber base materials are set simultaneously. Thus, occurrence of such misalignment and wrinkles can be suppressed. Further, the production efficiency can be improved as compared with the case where the sheets are sequentially set.

  In this embodiment, it is preferable to use a multiaxial base material described in USP 455045 or JP-T-2001-516406 as a fiber base material. An example of an enlarged view of the surface of the multiaxial substrate is shown in FIG. The multiaxial base material of this embodiment has a structure shown in FIG. 4B, and the fiber base material is 0 °, 90 °, + 30 ° -60 °, 90 °, −30 based on a predetermined rotation axis. The layers are laminated in a state of being rotated at 60 ° and + 60 °, and the reinforcing fibers are arranged along the substrate thickness direction Z to bond the layers of the fiber substrates. In this example, a multiaxial base material having a triaxial structure is used, but the invention is not limited to this, and a multiaxial base material having a five axis structure may be used. By using a multiaxial base material, the labor of base material lamination can be saved and the production efficiency can be increased.

  Moreover, it is preferable that a textile base material is a mesh base material as shown to FIG. 5 (A). When using a mesh substrate, it is preferable to select a mesh substrate in which the gap formed between the weaving yarns is larger than a predetermined threshold value. The degree of the size of the gap is preferably determined based on the value of Cf (cover factor). Cf (cover factor) is an index value indicating the ratio of yarn to the area of the fabric. Since the mesh base material provided with the deformability can be shaped into a complicated three-dimensional shape, a high-quality preform can be obtained even if the three-dimensional shape is complicated.

  The woven base material is preferably a fiber base material having a twill weave structure as shown in FIG. The twill weave structure is a structure that represents an oblique line in which a complete structure is formed from three or more warps and wefts, and the structure points are slanted continuously. In the twill weave, the length of the warp weft floats longer than the plain weave, and the woven fabric structure is loosened by that much, so it is smooth and rich in deformability. That is, since the lattice can be easily subjected to shear deformation, it is possible to shape the curved surface, and a high-quality preform can be obtained even if the target three-dimensional shape is complicated.

  It is preferable to form a notch in advance in accordance with the three-dimensional shape in the textile base material set in the shaping mold. FIG. 6A shows a prepared textile substrate. FIG. 6B shows a notch D formed therein. By providing a notch in the portion corresponding to the unevenness having a large step, it is possible to facilitate the deformation of the fiber base material and to prevent the generation of wrinkles and twists.

  It is preferable to arrange the patch base material E according to the three-dimensional shape on the fiber base material set in the shaping mold. FIG. 7A shows a state in which the fiber base is set in a shaping mold. FIG. 7B shows a state in which the patch base material E is disposed thereon. In a convex part with a large level difference, the fiber base material may open, and the density of the reinforcing fibers may be reduced. Moreover, the fiber base material may not exist in the part in which the notch D is formed. By arranging the patch base material in such a portion, the strength can be made uniform and the mechanical strength can be improved.

  The preform shaped by the shaping mold is conveyed to the manufacturing process of the fiber reinforced composite material. If necessary, a binder is applied to the preform after shaping. This is to improve handling. The binder only needs to be able to stabilize the form / shape of the preform, and it is preferable to use a thermosetting resin, a thermoplastic resin, rubber, starch, or the like.

  Next, a fiber-reinforced composite material is manufactured using the obtained preform. In the present embodiment, a fiber reinforced composite material is obtained using an RTM (Resin Transfer Molding) molding method. A preform obtained in a pair of male and female airtight molds and necessary insert parts are set. After setting, airtight mold clamping is performed, and a matrix containing resin is press-fitted and filled. This impregnates the preform with the matrix. The matrix of the fiber reinforced composite material is not particularly limited, and thermosetting resins such as phenol resin, unsaturated polyester resin, epoxy resin, vinyl ester resin, acrylic resin, and urethane resin can be used. As the thermoplastic resin, general-purpose plastics and engineering plastics can be used, but it is preferable to mainly use the latter. Examples of the engineering plastic include polyamide, polyacetal, polybutylene terephthalate, polycarbonate, polyphenylene sulfide, polyethersulfone, polyetheretherketone, nylon, polyimide, polyetherimide, and polyamideimide.

  After the matrix impregnation, the resin is cured by heating or the like. After the temperature is lowered, the mold is released to obtain a fiber-reinforced composite material shaped into the desired three-dimensional shape.

  By using a preform having no misalignment or wrinkles, the strength of the fiber-reinforced composite material can be improved.

  A fiber base material (CO 6343 manufactured by Toray Industries, Inc.) was set on a shaping mold 2 for shaping the fiber base material into a predetermined three-dimensional shape. The fiber base material in this state is shown in FIG. After setting the fiber base material to the shaping mold, each direction of A, B, C and D shown in FIG. 8 is 0 ° in the reference direction, + 45 °, −45 ° left and right from the reference direction, and 90 ° in the left direction. The fiber substrate was pressed by hand toward Thereafter, the shaping mold was clamped to obtain a preform. The appearance of the obtained preform was evaluated. In the appearance evaluation, the presence or absence of misalignment, the presence or absence of wrinkles, and the presence or absence of bridging were evaluated.

  The misalignment means that the crossing state between the warp and the weft in the initial state changes. The plain weave will be described as an example. In the plain weave substrate in the initial state, the warp and the weft are orthogonal to each other as shown in FIG. After the shaping, as shown in FIG. 9B, when the crossing state of the warp and the weft changes, it was determined that “missing” occurred.

  Wrinkle means that warp or weft fibers are twisted. The plain weave base material in the initial state has straight warps and wefts as shown in FIG. After shaping, when twisting was observed in the warp or weft as shown in FIG. 10 (B), it was determined that “wrinkles” had occurred.

  Bridging refers to a state in which the fiber base material is not stretched and the fiber base material is stretched. In a state where no bridging occurs, the fiber base material is in close contact with the shaping mold as shown in FIG. On the other hand, when bridging occurs, the fiber base material is stretched as shown in FIG. When the part that floated from the shaping mold was observed, it was judged that “bridging” occurred.

<Example 1>
In Example 1, a preform was obtained by pressing the fiber substrate along a direction away from the substantially central position B of the fiber substrate toward the end. The state of the preform of Example 1 is shown in FIG. The arrow shown in FIG. 12 corresponds to the reference direction 0 ° shown in FIG. As shown in FIG. 12, occurrence of misalignment, wrinkles and bridging was not observed in the preform of Example 1.

<Comparative Example 1>
In Comparative Example 1, a preform was obtained by pressing the fiber base set in the shaping mold from position A. Comparative Example 1 The state of the preform is shown in FIG. The arrow shown in FIG. 13 corresponds to the reference direction 0 ° shown in FIG. As shown in FIG. 13, occurrence of misalignment and wrinkles was observed at the position indicated by X1 of the preform of Comparative Example 1.

<Comparative example 2>
In Comparative Example 2, a preform was obtained by pressing the fiber base set in the shaping mold from position C. Comparative Example 2 The state of the preform is shown in FIG. The arrow shown in FIG. 14 corresponds to the reference direction 0 ° shown in FIG. As shown in FIG. 14, occurrence of misalignment and wrinkles was observed at the position indicated by X2 of the preform of Comparative Example 2.

<Comparative Example 3>
In Comparative Example 3, a preform was obtained by pressing the fiber base set in the shaping mold from position D. Comparative Example 3 The state of the preform is shown in FIG. The arrow shown in FIG. 15 corresponds to the reference direction 0 ° shown in FIG. As shown in FIG. 15, occurrence of misalignment and wrinkles was observed at the position indicated by X3 in the preform of Comparative Example 3.

  By pressing the approximate center of the fiber substrate first and then pressing in order from the approximate center toward the end, occurrence of misalignment, wrinkles, and bridging can be suppressed.

Second Embodiment
The second embodiment is characterized by a preform fiber base that is shaped into a predetermined three-dimensional shape using a shaping mold. Based on the technical idea of suppressing the occurrence of misalignment, wrinkles or bridging by pressing the fiber base toward the direction away from the approximate center to the end of the fiber base, this embodiment is a preform creation. Provided is a fiber base material that clearly indicates to the operator the position at which the fiber base material is pressed, the order of pressing, and the pressing direction.

  An example of the fiber base material of this embodiment is shown in FIG. A first point mark set in the approximate center of the fiber base 1 and an nth point mark set in the order of separation from the first point mark to the end of the fiber base (n is a natural number of 2 or more) are displayed. Has been. The first to n-point markers are preferably displayed together with numbers 1 to n. As shown in FIG. 16, the first point marker is displayed with a number (1st) at the center of the fiber base material. . Around that, n-th point signs numbered 2 to 11 are displayed in order of increasing distance from the first point. Further, in this example, the direction (a, b, c, d) is indicated by an arrow for a portion that is continuously pressed from substantially the center.

  The operator who shapes the fiber base, after setting the fiber base to the shaping mold, first presses the position where the first point mark is displayed, and then the number where the position where the point mark is displayed is given Hold in order. By using a fiber substrate on which such a sign is displayed in advance, the same effects as the method of the first embodiment can be obtained, and misalignments, wrinkles, or bridging can be generated even by non-experts. You can create a preform without.

<Third Embodiment>
The third embodiment is a preform manufacturing apparatus used in the manufacturing method of the first embodiment. FIG. 17A shows an outline of the configuration of the preform manufacturing apparatus 3 of the present embodiment. The preform manufacturing apparatus 3 of the present embodiment is configured so that a shaping mold 2 for shaping a fiber base into a predetermined three-dimensional shape and a predetermined portion of the fiber base 1 set in the shaping mold 2 at a predetermined timing. And a pressing device 3 for pressing. The pressing device 3 includes pressing rollers 31, 32, and 33 that can be driven three-dimensionally. The driving of the pressing rollers 31, 32 and 33 is independently controlled by the controller 35.

  A control method by the controller 35 will be described with reference to FIG. When the press function of the preform manufacturing apparatus 3 shown in FIG. 17A is activated, the controller 35 moves the press roller 31 to the upper part of the substantially central portion of the fiber base material so as to come into contact with the fiber base material. 31 is lowered and the substantially center part of the fiber base material is pressed down. This state is shown in FIG. As shown in FIG. 17B, the pressing roller 31 is in contact with the substantially central portion of the fiber base material.

  Thereafter, the controller 35 moves the pressing rollers 32 and 33 to the upper portions of the positions N and M that are separated from the approximate center of the fiber base toward the end, and the pressing rollers 32 and 33 are in contact with the fiber base. Lowering and pressing down the approximate center of the fiber substrate. This state is shown in FIG. As shown in FIG. 17C, the pressing rollers 32 and 33 are in contact with the positions N and M of the fiber base material.

  Thereafter, the controller 35 raises the pressing rollers 32 and 33 and moves them to positions S and T, lowers the pressing rollers 32 and 33 so as to contact the fiber base material, and presses the end of the fiber base material. . This state is shown in FIG. As shown in FIG. 17D, the pressing rollers 32 and 33 are in contact with the positions S and T of the fiber base material. 17A to 17D correspond to FIGS. 2A to 2D according to the manufacturing method of the first embodiment.

  In this example, the set substantially central portion and the positions N, S, M, and T are sequentially pressed. However, the pressing roller is rotated from the substantially central portion through the position N to the position S, and continuously. You may hold it down. The same applies to the position T from the center through position M. Moreover, although the fiber base material was pressed using the pressing roller in this example, it is not limited to this, A pin-shaped press and a bar-shaped press can be used. In addition, the drive mechanism of raising / lowering and horizontal movement of the pressing roller is not particularly limited.

  According to the preform manufacturing apparatus in which the pressing position and the pressing order can be controlled in this way, it is possible to automate the fiber substrate setting process currently being performed manually. In addition, by pressing the fiber base material in the direction away from the approximate center to the end, the same effect as the method of the first embodiment can be obtained, and the occurrence of misalignment, wrinkles, or bridging can be avoided. Reform manufacturing process can be automated.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

It is a figure which shows an example of the preform used with the manufacturing method of the preform of 1st Embodiment. It is a figure for demonstrating the procedure of the manufacturing method of the preform of 1st Embodiment, FIG. 2 (A) is the state which set the fiber base material, FIG. 2 (B) is the state which hold | suppressed the substantially center part, FIG. 2 (C) shows a state where a portion separated from the center is pressed, and FIG. 2 (D) shows a state where a portion further separated from the center is pressed. It is a figure which shows the state which accumulated and set the several fiber base material. (A) is an enlarged view of a multiaxial base material, (B) is a figure for demonstrating the structure of a multiaxial base material. (A) is a figure which shows a mesh base material, (B) is a figure which shows the fiber base material of a twill structure. (A) is a figure which shows the fiber base material before forming a notch, (B) is a figure which shows the fiber base material which formed the notch. (A) is a figure which shows the state which set the fiber base material, (B) is a figure which shows the state which has arrange | positioned the patch base material. It is a figure which shows the position pressed initially in an Example and a comparative example. It is a figure for demonstrating misalignment. It is a figure for demonstrating a wrinkle. It is a figure for demonstrating bridging. FIG. 3 is a diagram showing a state of a preform of Example 1. It is a figure which shows the state of the preform of the comparative example 1. It is a figure which shows the state of the preform of the comparative example 2. It is a figure which shows the state of the preform of the comparative example 3. It is a figure which shows an example of the fiber base material of 2nd Embodiment. It is a figure for demonstrating the operation | movement procedure of the preform manufacturing apparatus of 3rd Embodiment, FIG. 17 (A) is the state which set the fiber base material, FIG. 17 (C) shows a state in which a portion separated from the center is pressed, and FIG. 17 (D) shows a state in which a portion further separated from the center is pressed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 10 ... Fiber base material for preform 2 ... Mold for preform 3 ... Preform manufacturing apparatus 31, 32, 33 ... Pressing roller 35 ... Controller

Claims (11)

Using a shaping mold, a preform manufacturing method for shaping a fiber substrate into a predetermined three-dimensional shape,
Setting the fiber substrate in the shaping mold;
Pressing the central portion set at the approximate center of the fiber base set in the shaping mold; and
A step of continuously pressing the fiber substrate with a pressing roller in a direction away from the approximate center of the fiber substrate to the end.   The preform manufacturing method according to claim 1, wherein a plurality of fiber base materials are stacked and set on the shaping mold.   The preform manufacturing method according to claim 1, wherein the fiber base material is a multiaxial base material.   The preform manufacturing method according to claim 1, wherein the fiber base material is a mesh base material.   The preform manufacturing method according to claim 1, wherein the fiber base material is a twill weave structure.   The preform manufacturing method as described in any one of Claims 1-5 which sets the fiber base material which formed the notch according to the said predetermined | prescribed solid shape to the said shaping mold.   The preform manufacturing method as described in any one of Claims 1-6 which has a step which arrange | positions a patch base material according to the said predetermined | prescribed three-dimensional shape in the fiber base material set to the said shaping mold.   A method for producing a fiber-reinforced composite material, further comprising a step of impregnating a preform containing the resin into the preform obtained by the production method according to any one of claims 1 to 7, and a step of curing the resin. . A preform fiber substrate shaped into a predetermined three-dimensional shape using a shaping mold,
The position to be pressed against the fiber base, the order of pressing, and the direction in which the portion to be pressed continuously are clearly indicated, and the first point mark set at the approximate center of the fiber base and the fiber from the first point A fiber substrate on which n-th point markers (n is a natural number of 2 or more) set in the order of separation from the end of the substrate are displayed. The fiber base material according to claim 9 , wherein the first point mark to the nth point mark are displayed together with a number from 1 to n. A shaping mold for shaping the fiber substrate into a predetermined three-dimensional shape;
A preform manufacturing apparatus having a pressing device that presses a predetermined portion of the fiber base set in the shaping mold at a predetermined timing,
The pressing device first presses the central portion set at the approximate center of the fiber base, and then one or more portions set at positions spaced from the approximate center of the fiber base toward the end. A preform manufacturing apparatus comprising a controller that controls the center portion to be continuously pressed by a pressing roller from the central portion.