JP4718694B2 - Manufacturing method of fiber reinforced composite material molded article - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for manufacturing a three-dimensional fiber-reinforced composite material molded product, and more particularly, to a fiber-reinforced composite material molded product suitable for manufacturing a three-dimensional molded product having a large curvature using a prepreg. The present invention relates to a manufacturing method and a molding apparatus.
[0002]
[Prior art]
Conventionally, when molding a fiber reinforced composite material molded into a three-dimensional shape such as a container shape using a prepreg obtained by impregnating a resin into a reinforcing fiber and semi-cured, the three-dimensional shape has a gentle convex shape with a small curvature. Or in the case of a concave shape, it can shape | mold by pressing and extending a prepreg from both surfaces with the press type | mold which makes a desired shape.
[0003]
For example, in the golf club manufacturing method disclosed in Japanese Patent Laid-Open No. 6-98953, a head portion of a three-dimensional golf club is divided into a plurality of parts when preformed. The preform of each part is obtained by press-molding a prepreg cut into a predetermined shape with a press die. Each part of the preformed head and the preformed shaft are inserted into a hollow mold, pressure is applied from the inside of the preformed product, heat-molded, and joined and integrated with the golf club. Yes.
[0004]
However, in the method of press molding a three-dimensional molded product using a prepreg using a prepreg, when the molded product has a sharp convex shape or concave shape with a large curvature, a sheet-shaped prepreg is placed on the press mold surface. And when it is press-molded, wrinkles will enter. For this reason, when forming into a three-dimensional shape with a large curvature, a notch or notch is partially formed in advance in the prepreg, and the edge portions of the notch or notch are overlapped so as not to be wrinkled. Are molded.
[0005]
For example, when forming into a hemispherical shape, the prepreg is first cut into a circle. Then, as shown in FIG. 7, a plurality of cuts 3b are formed radially at equal intervals leaving the central region 3a of the circular prepreg 3, or the central region 4a of the circular prepreg 4 is left as shown in FIG. Notches 4b are formed radially at equal intervals. Thereafter, the center regions 3a and 4a of the circular prepregs 3 and 4 are aligned with the apex portion of the press die 20 having the hemispherical convex portion 20a shown in FIG. 9, or the bottom central portion of the press die 21 having the hemispherical concave portion 21a shown in FIG. The hemispherical press die 20 or 21 is laminated according to the above. At this time, adjacent edge portions of the notch 3b or the notch 4b are overlapped with each other. Then, the other press die is put on and press-molded to form a molded product having a hemispherical shape as a whole.
[0006]
The cuts 3b and the cutouts 4b are formed with a number and a length such that the prepregs 3 and 4 are not wrinkled. In particular, when the cutout 4b is formed, when the prepregs at the end edge portions are overlapped, the excess prepreg can be removed to such an extent that there is no gap between the end edges, so that the weight of the molded product can be reduced.
[0007]
[Problems to be solved by the invention]
By the way, conventionally, the process of placing the prepreg on a press die and overlapping the edge portions of the notches or notches is usually performed manually. Therefore, it is insufficient in terms of stability, uniformity and productivity of the quality of the molded product. In addition, when performing press molding with the other side press mold, wrinkles are likely to occur due to being drawn in, etc., and the molded fiber that requires a high degree of strength and appearance because it disturbs the array of reinforcing fibers, the above method is Not adopted.
[0008]
The present invention has been made to solve the conventional problems as described above, and a specific object of the present invention is to use a prepreg cut into a predetermined shape to form a three-dimensional shape by press molding. In a method and a molding apparatus for manufacturing a molded product, there is no wrinkle in the molded product, and a method for manufacturing a fiber-reinforced composite material molded product that can stably and efficiently produce a molded product of uniform quality. To provide an apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the basic configuration of the invention according to claim 1 is that a fiber-reinforced resin prepreg cut into a predetermined shape is formed with two or more cuts or notches, and adjacent to the cuts or cuts. In the method of manufacturing the fiber reinforced composite material molded article having a three-dimensional shape by overlapping the edge portions to be formed, the partially separated piece separated by the notch or notch is molded into a three-dimensional shape by press molding, A part of the remaining separation piece is overlapped with the partial separation piece by press molding, and the whole is formed into a desired three-dimensional shape.
[0010]
In addition, the fiber reinforced composite material molded product in the present invention is not only a final molded product that can be a product itself, but also a preformed product before being formed into a final product by joining and integrating with other parts later. Is also included.
[0011]
According to the manufacturing method described above, first, the partially separated piece separated by the notch or notch is formed into a three-dimensional shape by hot press molding, and then the remaining separated piece is separately formed on the partially separated piece by press molding. Since the portions are overlapped, the operation is easy, and there is no occurrence of wrinkles or disturbance of the reinforcing fibers due to the drawing even when the mold is clamped.
[0012]
Furthermore, according to the second aspect of the present invention, the method includes positioning and setting a predetermined part of a press die using the partially separated piece as a positioning piece.
In this way, by using the partially separated piece as a positioning piece, molding can be performed with high precision, work efficiency can be improved, and a high-quality molded product can be stably manufactured. Further, since the molding can be automated, the manufacturing efficiency is remarkably improved.
[0013]
In the invention according to claim 3 of the present invention, a prepreg in which carbon fibers are used as reinforcing fibers and the carbon fibers are aligned in one direction is used. Alternatively, the invention according to claim 4 uses a prepreg which is a carbon fiber bi-directional woven fabric in which carbon fibers are used as reinforcing fibers and the carbon fibers are used as warps and wefts. These can be appropriately selected according to the use of the fiber-reinforced composite material and the required strength.
[0014]
In the invention according to claim 5, a plurality of the prepregs are stacked and simultaneously molded. By stacking a plurality of prepregs in this way, a fiber-reinforced composite material molded product having a desired thickness can be manufactured.
[0015]
Furthermore, as a molding apparatus suitable for the manufacturing method described above, the invention according to claim 6 includes first and second pairs of press dies, and is suitably applied to the invention methods according to claims 1 to 5. A molding apparatus for molding a fiber-reinforced composite material molded article having a three-dimensional shape, comprising a first and second pair of press dies, wherein the first press mold is a back-side three-dimensional molded article. A projection part on which the remaining separation piece is placed on a part of the negative shape, and a concave groove part on which the partial separation piece is positioned and placed on a remaining part of the negative shape adjacent to the projection part, The press die is characterized in that it has a fitting shape that fits into the protrusion on a part of the negative shape of the surface side three-dimensional molded product.
[0016]
The partial separation piece of the prepreg is positioned and set on the protrusion of the first press die, and the partial separation piece is press-molded with the second press die.
After that, the remaining separation piece is bent by a press die having a negative shape of the back surface side three-dimensional molded product and a press die having a negative shape of the front surface side three-dimensional shape molding product, and partially overlaps the separation piece. The whole is press-molded into a three-dimensional shape. These press dies may be separate from the first and second press dies. For example, the first and second press dies are configured by using a movable piece member with a concavo-convex portion, It is also possible to press-mold the whole into a three-dimensional shape using the first and second press dies.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
[0018]
For example, when producing a hemispherical fiber-reinforced composite material molded product, first, the prepreg is cut into a circle. Then, as shown in FIG. 5, the circular prepreg 1 is formed with four sets of two parallel line-like cuts 1b, leaving the central portion 1a, in a cross shape, and the periphery of the rectangular prepreg 1 as a partial separation piece of the present invention. The separated piece 1c is separated into a fan-shaped separated piece 1d which becomes the remaining separated piece . The cut shape of the prepreg is not necessarily circular, and can be cut into an appropriate shape so as to have a required edge shape.
[0019]
Next, of the circular prepreg 1 in which the cuts 1b are formed, first, only the rectangular separating piece 1c is formed to be hemispherically curved, and then the fan-shaped separating piece 1d is bent to be hemispherical to form the rectangular separating piece 1c. Mold in a state where a part is piled up. A specific molding method will be described.
[0020]
When only the rectangular separating piece 1c is formed into a hemispherical shape, press dies 10, 11 shown in FIGS. 2 and 3 are used. A first press die 10 shown in FIG. 2 has a negative part of a hemispherical shape on the back side of the molded product, a cross-shaped hemispherical concave groove portion 10a, and the other part, that is, a fan-shaped separation piece of the circular prepreg 1 At a position corresponding to 1d, a fan-shaped protrusion 10b having a flat upper surface protrudes to the same height as the top of the 10a hemisphere.
[0021]
On the other hand, the second press die 11 shown in FIG. 3 has a negative shape to be fitted into the hemispherical concave groove portion 10a, and is fitted with the first press die 10 with a predetermined clearance. The second press die 11 has a circular opening 11b formed at the center of the frame 11a. The circular opening 11b is fitted between the fan-shaped protrusions 10b and is in close contact with the surface of the cross-shaped groove 10a. A hemispherical cross-shaped protrusion 11c is formed.
[0022]
In order to form using the press dies 10 and 11, first, the circular prepreg 1 is placed on the first press die 10. At this time, as shown in FIG. 4, the central portion 1 a of the circular prepreg 1 is placed on the top of the hemisphere 10 a of the first press die 10, and the rectangular separating piece 1 c is formed into a cross-shaped hemispherical recess of the press die 10. The fan-shaped separating piece 1d is positioned on the fan-shaped protrusion 10b of the press die 10 while being along the groove 10a.
[0023]
By using the press die 10 having such a shape, the circular prepreg 1 is always in a fixed position with respect to the press die 10 by the cross-shaped concave groove portion 10a formed between the fan-shaped protrusions 10b. It can be positioned and placed accurately. In addition, since the circular prepreg 1 has two sets of cuts 1b parallel to each other, the rectangular separation piece 1c between the two cuts 1b is formed by the press mold 10 on which the adjacent fan-shaped separation pieces 1d are placed. There is no interference with the fan-shaped protrusion 10b. In order to avoid such interference, the cuts 1b are preferably formed so as to be parallel to each other or narrow toward the outer periphery as described above.
[0024]
In this state, the second press die 11 is fitted to the first press die 10, and the central portion 1a of the circular prepreg 1 and the rectangular separation piece 1c are connected to the cross-shaped concave groove portion 10a of the first press die 10 and the first groove 10a. 2. Press-molding with the hemispherical cross-shaped projection 11c of the press die 11.
[0025]
Next, as shown in FIGS. 5 and 9, the circular prepreg 1 in which the central portion 1 a and the rectangular separating piece 1 c are formed in a hemispherical shape on the third press die 20 having the hemispherical convex portion 20 a, The center of the convex portion 20a and the center of the central portion 1a are aligned and placed, and the fourth press die 21 having the hemispherical concave portion 21a shown in FIG. Then, the edge portion of the fan-shaped separation piece 1d is overlaid on the surface of the edge portion of the rectangular separation piece 1c.
[0026]
At this time, since the central portion 1a of the circular prepreg 1 and the rectangular separating piece 1c are formed in a hemispherical shape as described above, the fan-shaped separating piece 1d is a part of the rectangular separating piece 1c without wrinkles or the like. It can be easily stacked on the surface, and the fan-shaped separation piece 1d is not wrinkled by being pulled in even during clamping. In this state, it is preformed into a hemispherical shape and further heated to form a fiber reinforced composite material molded product.
[0027]
Thus, in forming a hemispherical fiber-reinforced composite material molded product, the present invention includes a first step of forming the cross-shaped portion of the central portion 1a and the rectangular separating piece 1c into a hemispherical shape, and the remaining sector shape. The separation piece 1d is press-molded through two steps including a second step of forming a part of the separation piece 1d on the rectangular separation piece 1c and forming a hemisphere. According to this method, the circular prepreg 1 is accurately positioned in the press die using the cut 1b in the first step, so that a molded product of uniform quality can be manufactured. In the second step, approximately half of the shape is formed into a hemispherical shape, so that the remaining portion is molded and integrated with the previously molded portion without causing wrinkles.
[0028]
In the above-described embodiment, the circular prepreg 1 in which the notch 1b is formed is adopted. However, like the circular prepreg 2 shown in FIG. 6, the notch 2b is formed in the crossed shape leaving the central portion 2a. The peripheral edge may be separated into a rectangular separation piece 2c and a sectoral separation piece 2d. In this case, the overlap between the rectangular separation piece 2c and the fan-shaped separation piece 2d adjacent to each other with the notch 2b interposed therebetween can be minimized to such an extent that no gap is generated therebetween, and unnecessary overlap is removed. be able to. Therefore, the thickness difference in the overlapping portion can be reduced.
[0029]
In the above-described embodiment, the above-described two steps are performed using separate press dies. For example, the fan-shaped protrusion 10b of the first press die 10 is configured by a movable piece member, It is also possible to mold with a set of press dies by fitting a movable piece member into the circular opening 10a of the second press die 11.
[0030]
Furthermore, the shape of the protrusion or the recess does not necessarily need to be completely matched with the cut shape of the prepreg, and may be enough if it can be bent or curved into a predetermined three-dimensional shape or overlapped.
[0031]
Further, by providing a clearance that allows a plurality of prepregs to be laminated between the upper and lower press molds, a plurality of prepregs can be molded and integrated into a three-dimensional shape at the same time to produce a thick molded product. At this time, a plurality of prepregs may be formed with the same cutting position, or the cutting is intentionally slightly shifted, and the overlapping portions of the cutting edges are shifted in the upper and lower prepregs to reduce the difference in wall thickness. In addition, the occurrence of a step can be improved. At this time, the protrusions of the press die need to maintain the respective cutting positions and distances. Furthermore, prepregs made of different materials such as glass fiber, resin fiber, and metal fiber can be molded simultaneously or separately and integrally molded.
[0032]
As the prepreg, a sheet in which reinforcing fibers are aligned in one direction and a matrix resin impregnated, for example, a unidirectional carbon fiber reinforced epoxy resin prepreg can be used. Furthermore, unidirectional carbon fiber reinforced epoxy resin prepregs are laminated in multiple layers so that the fibers are in two directions of 0 ° direction and 90 ° direction. It can also be laminated and molded repeatedly. In that case, the strength by the reinforcing fiber is obtained in the other direction, and the strength balance is easily obtained.
[0033]
Alternatively, for example, a bi-directional woven carbon fiber reinforced epoxy resin prepreg in which a woven fabric using reinforcing fibers for warp and weft is impregnated with a matrix resin may be employed.
[0034]
The manufacturing method according to the present invention can be applied to molding of various three-dimensional shapes such as a rectangular box shape and a spindle shape, without limiting the fiber-reinforced composite material molded product to a hemispherical shape. In addition, this molded product is not limited to the final product. For example, a container-shaped preform is molded by the method of the present invention, and then the preform is combined in a mold, and a hollow structure is formed by internal pressure molding. It is also possible to produce a final product.
The above-described method for manufacturing a molded article according to the present invention is preferably applied to, for example, manufacturing a three-dimensional helmet or a golf head.
[0035]
Hereinafter, the present invention will be described with specific examples and comparative examples.
(Example)
“Pyrofil TR350H175S” (carbon fiber content: 56% by volume) manufactured by Mitsubishi Rayon Co., Ltd. is used as a carbon fiber woven cloth reinforced epoxy resin prepreg, laminated so that the fibers are oriented at 0 ° and 90 °. The preform was molded into a shape.
[0036]
First, the prepreg was cut into a circle, and a cut 1b was formed as shown in FIG. The central portion 1a of the circular prepreg 1 is placed on the top of the cross-shaped hemisphere 10a of the first press mold 10 shown in FIG. 2, the rectangular separating piece 1c is placed along the hemispherical concave groove 10a, and the fan-shaped separating piece 1d is placed. It is positioned on the fan-shaped protrusion 10b of the press die 10. Next, the second press die 11 shown in FIG. 3 is fitted to the first press die 10, and the central portion 1a and the rectangular separating piece 1c are press-formed into a hemispherical shape. Before the press dies 10 and 11 were fitted, in order to soften the prepreg, it was heated at 80 ° C. for 10 seconds with an infrared heater. Thereafter, the inside of the press molds 10 and 11 was cooled by air blow at 20 ° C., and then the shape of the prepreg was fixed and demolded.
[0037]
The extracted prepreg is placed on the hemispherical convex portion 20a of the third press mold 20 shown in FIG. 5 so that the top of the convex portion 20a and the central region of the prepreg 1 are aligned, and an infrared heater at 80 ° C. for 10 seconds. It softens by heating, and covers the fourth press die 21 shown in FIG. 10 to curve the fan-shaped separating piece 1d into a hemispherical shape and adhere it to the rectangular separating piece 1c. Then, after cooling to 20 ° C. by air blow in the press mold, the prepreg shape was fixed and demolded to obtain a preform molded product.
[0038]
This preform molded product was set in a molding die, bag-molded at a pressure of 4 kgf / cm ² , and cured at 120 ° C. for 2 hours to obtain a molded product. A product with good strength and appearance and excellent production stability could be obtained.
[0039]
(Comparative example)
A circular prepreg 1 with a cut as shown in FIG. 1 is molded in the same manner as in the above-described embodiment except that only the press dies 20 and 21 shown in FIGS. Went. As a result, the prepreg was drawn into the press mold, wrinkles and fiber disturbance occurred, and a preform with sufficient quality could not be obtained.
[0040]
As described above, in the method for producing a fiber-reinforced composite material molded product of the present invention, even a three-dimensional shape with a large curvature can be efficiently produced with uniform quality without causing wrinkles. Is possible. Furthermore, it is possible to automate conventional manual lamination, and it is possible to further improve quality stability and manufacturing efficiency.
[Brief description of the drawings]
FIG. 1 is a plan view of a prepreg preferably used in the production method of the present invention.
FIG. 2 is a schematic perspective view of a first press die preferably used during the first molding in the manufacturing method of the present invention.
3 is a rear perspective view of a second press die corresponding to the first press die of FIG. 2; FIG.
FIG. 4 is an explanatory view showing a state at the time of first molding in the production method of the present invention.
FIG. 5 is an explanatory view showing a state during second molding in the production method of the present invention.
FIG. 6 is a plan view of another prepreg preferably used in the production method of the present invention.
FIG. 7 is a plan view of a prepreg used in a conventional manufacturing method.
FIG. 8 is a plan view of another prepreg used in the conventional manufacturing method.
FIG. 9 is a schematic perspective view of a press die that is used in a conventional manufacturing method and is preferably used during second molding in the manufacturing method of the present invention.
10 is a schematic rear perspective view of a press die corresponding to the press die of FIG. 9. FIG.
[Explanation of symbols]
1 circular prepreg 1a center part 1b notch 1c rectangular separation piece (partial separation piece)
1d Fan-shaped separation piece (remainder separation piece)
2 Circular prepreg 2a Center part 2b Notch 2c Rectangular separation piece (partial separation piece)
2d Fan-shaped separation piece (remainder separation piece)
DESCRIPTION OF SYMBOLS 3 Circular prepreg 3a Center part 3b Notch 4 Circular prepreg 4a Center part 4b Notch 10 1st press die 10a Cross-shaped groove part (concave part)
10b Fan projection (projection)
11 Second press die 11a Frame 11b Circular opening (fit shape)
11c Hemispherical cross section 20 Third press die 20a Hemispherical convex portion 21 Fourth press die 21a Hemispherical concave portion

Claims (6)

Two or more cuts (1b) or notches (2b) are formed in the fiber reinforced resin prepreg (1, 2) cut into a predetermined shape, and the adjacent edge portions of the notches or notches are overlapped and molded. In a method of manufacturing a fiber-reinforced composite material molded article having a three-dimensional shape,
The partially separated pieces (1c, 2c) separated by the notches (1b) or notches (2b) are molded into a three-dimensional shape by press molding,
Next, a part of the remaining separation pieces (1d, 2d) is overlapped by press molding on the partial separation pieces (1c, 2c) , and the whole is formed into a desired three-dimensional shape.
A method for producing a fiber-reinforced composite material molded article. The method of manufacturing a fiber-reinforced composite material molded article according to claim 1, wherein the partial separation piece (1c, 2c) is used as a positioning piece and positioned and set at a predetermined portion of a press die.   The method for producing a fiber-reinforced composite material according to claim 1 or 2, wherein a carbon fiber is used as a reinforcing fiber and a prepreg in which the carbon fiber is aligned in one direction is used.   The manufacturing method of the fiber reinforced composite material of Claim 1 or 2 using the prepreg which is a carbon fiber bi-directional woven fabric which used the carbon fiber as a reinforced fiber and the carbon fiber was used for the warp and the weft.   The manufacturing method of the fiber reinforced composite material molded product according to any one of claims 1 to 4, wherein a plurality of the prepregs are stacked and simultaneously molded. A molding apparatus for molding a fiber-reinforced composite material molded article having a three-dimensional shape for carrying out the manufacturing method according to claim 1 ,
Comprising press dies (10, 11) as first and second pairs;
The first press die (10) includes a protrusion (10b) on which the remaining separation piece (1d, 2d) is placed on a part of the negative shape of the back side three-dimensional molded product, and the protrusion (10b). A concave groove (10a) on which the partial separation piece (1c, 2c) is positioned and placed in the negative-shaped remaining portion adjacent to
The second press die (11) has a fitting shape (11b) that fits into the protrusion (10b) in a part of the negative shape of the surface-side three-dimensional molded product.
An apparatus for molding a fiber-reinforced composite material molded product.

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