JP2002240068A - Method for manufacturing molded article comprising fiber reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus capable of stably molding a molded article comprising a fiber reinforced composite material having a three- dimensional shape and uniform quality with high efficiency using a prepreg cut into a predetermined shape without generating wrinkles. SOLUTION: The prepreg (1) cut into the predetermined shape is separated into a central part (1a), rectangular separated pieces (1c) and fan-shaped separated pieces (1d). At first, the central part (1a) and the rectangular separated pieces (1c) are positioned and set to the recessed grooves (10e) of a press mold (10), the fan-shaped separated pieces (1d) are positioned and set to fan-shaped projections (10b), and only the central part (1a) and the rectangular separated pieces (1c) are molded into a three-dimensional shape by press molding. Subsequently, the fan-shaped separated pieces (1d) are partially superposed on a part of the rectangular separated pieces (1c) previously molded by separate press molding, and the whole is formed into a three-dimensional shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for producing a fiber-reinforced composite material having a three-dimensional shape.
In particular, the present invention relates to a method and an apparatus for producing a fiber-reinforced composite material molded article suitable for producing a three-dimensional molded article having a large curvature using a prepreg.

[0002]

2. Description of the Related Art Conventionally, when a fiber-reinforced composite material molded article having a three-dimensional shape such as a container is formed using a prepreg obtained by impregnating a resin into a reinforcing fiber and semi-curing, the three-dimensional shape has a curvature. In the case of a small gentle convex or concave shape, the prepreg can be formed by pressing and stretching the prepreg from both sides with a press die having a desired shape.

For example, in a golf club manufacturing method disclosed in Japanese Patent Application Laid-Open No. Hei 6-98953, when a golf club head having a three-dimensional shape is preformed, it is divided into a plurality of parts. The preform of each part is
It is obtained by press-molding a prepreg cut into a predetermined shape using a press die. Each part of the preformed head and the preformed shaft are inserted into a hollow mold, and pressure is applied from the inside of the preformed article to heat-mold and integrated into a golf club. I have.

However, in the method of press-forming a three-dimensional molded product using a prepreg using a press mold, when the molded product has a sharp convex or concave shape having a large curvature, a sheet-shaped prepreg is formed on the press mold surface. When the sheet is placed and pressed and formed, wrinkles are formed. Therefore, when forming into a three-dimensional shape having a large curvature, a notch or a notch is partially formed in the prepreg in advance, and the edges of the notch or the notch are overlapped with each other and laminated so that wrinkles do not enter. Molding.

For example, when molding into a hemispherical shape, first, the prepreg is cut into a circular shape. Then, as shown in FIG. 7, a plurality of cuts 3b are formed radially at equal intervals while leaving the central region 3a of the circular prepreg 3, or as shown in FIG. 8, leaving the central region 4a of the circular prepreg 4. The notches 4b are formed radially at equal intervals. Thereafter, the central regions 3a and 4a of the circular prepregs 3 and 4 are aligned with the apexes of the press mold 20 having the hemispherical convex portions 20a shown in FIG. 9 or the bottom central portion of the press mold 21 having the hemispherical concave portions 21a shown in FIG. Hemispherical press mold 20 or 21 according to
To be laminated. At this time, adjacent edge portions of the cuts 3b or the notches 4b are overlapped with each other. Then, the other mold is put on and press-molded to form a hemispherical molded product as a whole.

The notches 3b and the notches 4b are formed in such a number and length that no wrinkles are formed on the prepregs 3, 4. In particular, when the notch 4b is formed, when the prepregs at the edge portions are overlapped, excess prepreg can be cut off to the extent that no gap is formed between the edges, so that the weight of the molded product can be reduced.

[0007]

Conventionally, the step of placing a prepreg on a press die and superposing the edges of the cuts or cuts is usually performed manually. Therefore, the stability, uniformity and productivity of the quality of the molded product are insufficient. In addition, when the press molding is performed by covering with the other press mold, wrinkles are easily formed by being drawn in, and the arrangement of the reinforcing fibers is disturbed. Not adopted.

The present invention has been made to solve the above-mentioned conventional problems, and a specific object thereof is to use a prepreg cut into a predetermined shape and press-mold a three-dimensional fiber-reinforced fiber. A method and apparatus for manufacturing a molded article of a composite material, in which a wrinkle does not occur in the molded article, and a fiber-reinforced composite material molded article can be produced stably and efficiently with uniform quality. It is to provide a method and a molding device.

[0009]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 of the present invention is to form two or more cuts or notches in a fiber reinforced resin prepreg cut into a predetermined shape. In a method of manufacturing a molded article of a fiber-reinforced composite material having a three-dimensional shape by overlapping and molding adjacent edge portions of notches or notches, a partially separated piece separated by the notches or notches is press-formed. It is characterized in that it is formed into a three-dimensional shape, a part of the remaining part is overlapped on the partially separated piece by press molding, and the whole is formed into a desired three-dimensional shape.

[0010] The fiber-reinforced composite material molded article in the present invention is not limited to a final molded article which can itself be a product, but also a preliminary molded article which is later formed into a final product by, for example, joining and integrating with other parts. It also includes molded articles.

According to the above-described manufacturing method, first, the partially separated piece separated by the notch or notch is formed into a three-dimensional shape by press molding, and then the remaining part is separately formed into the partially separated piece by press molding. Since the parts are overlapped with each other, the work is easy, and the wrinkles and the arrangement of the reinforcing fibers are not disturbed due to the drawing in the mold clamping.

Further, according to the second aspect of the present invention,
The method includes positioning and setting the partially separated piece as a positioning piece at a predetermined portion of a press die. By using the partially separated piece as the positioning piece in this way, molding can be performed with high precision, and the working efficiency is improved, and a high-quality molded product can be stably manufactured. Further, since the molding can be automated, the production efficiency is remarkably improved.

In the invention according to the third aspect of the present invention, a prepreg in which the carbon fibers are aligned in one direction is used as the reinforcing fibers. Alternatively, in the invention according to claim 4, a prepreg which is a carbon fiber bidirectional woven fabric using carbon fibers as reinforcing fibers and the carbon fibers as warp and weft is used. These can be appropriately selected according to the use of the fiber-reinforced composite material, the required strength, and the like.

Further, in the invention according to claim 5, a plurality of the prepregs are stacked and molded simultaneously. By laminating a plurality of prepregs in this way, a fiber-reinforced composite material molded article having a desired thickness can be manufactured.

Further, as a molding apparatus suitable for the above-described manufacturing method, the invention according to claim 6 of the present invention provides a molded article of a fiber-reinforced composite material having a three-dimensional shape, comprising first and second pairs of press dies. A molding apparatus, wherein the first press die comprises:
The second press die has a shape to be fitted to the protrusion on a part of the negative shape of the front-side three-dimensional molded product, the protrusion having a portion on the negative shape of the back-side three-dimensional molded product. It is characterized by having.

The partially separated piece of the prepreg is positioned and set on the protrusion of the first press die, and the partially separated piece is press-formed with the second press die. afterwards,
A press die having a negative shape of the backside three-dimensional molded product as a whole, and a press die having a negative shape of the front surface three-dimensional molded product as a whole, bending the remaining separated pieces, partially overlapping the separated pieces, The whole is press-formed into a three-dimensional shape. Note that these press dies may be separate from the first and second press dies, for example, the first and second press dies.
The press die is formed by using a movable piece member for the concave and convex portions.
And it is also possible to press-mold the whole into a three-dimensional shape by the second press die.

[0017]

Embodiments of the present invention will be specifically described below with reference to the drawings.

For example, when manufacturing a hemispherical fiber-reinforced composite material molded article, first, the prepreg is cut into a circular shape. As shown in FIG. 5, the circular prepreg 1 has four sets of two parallel linear cuts 1b excluding the central portion 1a.
It is formed into a cross, and its periphery is separated into a rectangular separating piece 1c and a fan-shaped separating piece 1d. Note that the cut shape of the prepreg does not necessarily have to be circular, and the prepreg can be cut into an appropriate shape so as to have a required edge shape.

Next, of the circular prepreg 1 in which the cuts 1b are formed, first, only the rectangular separating piece 1c is formed into a hemispherical shape, and then the fan-shaped separating piece 1d is bent into a hemispherical shape to form the rectangular separating piece 1d. It is molded in a state where a part is overlapped on the piece 1c. The specific molding method will be described.

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. The first press die 10 shown in FIG. 2 has a hemispherical negative part, a cross-shaped hemispherical concave groove 10
a, a fan-shaped projection 10b having a flat upper surface is protruded to a position corresponding to the fan-shaped separating piece 1d of the circular prepreg 1 to a height substantially equal to the top of the hemisphere 10a. ing.

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 10a, and fits with the first press die 10 with a predetermined clearance. . The second press die 11 has a circular opening 11b formed in the center of a frame 11a.
A hemispherical cross-shaped protrusion 11c fitted between the sector-shaped protrusions 10b and in close contact with the surface of the cross-shaped concave groove 10a.
Are formed.

In order to form using the press dies 10, 11, first, the circular prepreg 1 is placed on the first press dies 10. At this time, as shown in FIG. 4, the central portion 1a of the circular prepreg 1 is placed on the top of the hemisphere 10a of the first press die 10, and the rectangular separation piece 1c is cross-shaped in the cross-shaped hemisphere of the press die 10. The fan-shaped separating piece 1d is located on the fan-shaped projection 10b of the press die 10 along the groove 10a.

By using the press mold 10 having such a shape, the circular prepreg 1 is always fixed to the press mold 10 by the cross-shaped concave grooves 10a formed between the fan-shaped projections 10b. Position can be accurately positioned and placed. Further, in the circular prepreg 1, since a pair of cuts 1b are parallel, a rectangular separating piece 1c between the two cuts 1b is
There is no interference with the fan-shaped projection 10b of the press die 10 on which the adjacent fan-shaped separating piece 1d is placed. For the purpose of avoiding such interference, it is preferable that the cuts 1b are formed so as to be parallel to each other as described above or to become narrower toward the outer periphery.

In this state, the second press die 11 is fitted into the first press die 10, and the central portion 1 a of the circular prepreg 1 and the rectangular separating piece 1 c are cross-shaped in the first press die 10. Press forming is carried out by 10a and the hemispherical cross-shaped protrusion 11c of the second press die 11.

Next, as shown in FIGS. 5 and 9, a central portion 1a is placed on a third press mold 20 having a hemispherical convex portion 20a.
A circular prepreg 1 in which a hemispherical shape and a rectangular separating piece 1c are formed is placed with the center of the convex portion 20a and the center of the central portion 1a aligned with each other, and the hemispherical concave portion shown in FIG. The fourth press die 21 having 21a is fitted into the third press die 20 and press-formed, and the edge portion of the fan-shaped separating piece 1d is overlapped with the surface of the edge portion of the rectangular separating piece 1c.

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 formed without wrinkles or the like. Can be easily overlapped on a part of the surface, and no wrinkles are generated on the fan-shaped separating piece 1d due to being pulled in at the time of mold clamping. In this state, a preform is formed into a hemispherical shape, and further heated to form a fiber-reinforced composite material molded product.

As described above, in forming a hemispherical fiber-reinforced composite material molded article, the present invention provides a first step of forming the cross-shaped portion of the central portion 1a and the rectangular separating piece 1c into a hemispherical shape, The remaining fan-shaped separation piece 1d is press-formed through a second step of partially overlapping the rectangular separation piece 1c and forming a hemispherical shape. According to this method, in the first step, the circular prepreg 1
Since it is accurately positioned on the press die using b, a molded product of uniform quality can be manufactured. Also, in the second step, almost half of it is shaped into a hemisphere,
The remaining part is formed and integrated into the previously formed part without wrinkling.

In the above-described embodiment, the circular prepreg 1 having the cuts 1b is employed. However, as in the circular prepreg 2 shown in FIG.
A notch 2b may be formed in the cross, leaving a, and the periphery may be separated into a rectangular separating piece 2c and a fan-shaped separating piece 2d. In this case, the overlap between the rectangular separating piece 2c and the fan-shaped separating piece 2d adjacent to each other with the notch 2b interposed therebetween can be minimized to the extent that no gap is formed between them, and unnecessary overlap is removed. be able to. Therefore, the difference in wall thickness of the overlapping portion can be reduced.

In the above-described embodiment, the above-described two steps are performed using separate press dies. For example, the sector-shaped protrusion 10b of the first press die 10 is constituted by a movable piece member. It is also possible to form by a set of press dies, for example, by fitting a movable piece member to the circular opening 10a of the second press die 11.

Further, the shapes of the projections and the concave portions do not necessarily have to completely match the cut shapes of the prepreg, but it is sufficient if the shapes can be bent, bent or overlapped into a predetermined three-dimensional shape.

Also, by providing a clearance for laminating and molding a plurality of prepregs between the upper and lower press dies, a plurality of prepregs can be simultaneously molded into a three-dimensional shape and integrated to produce a thick molded product. . On this occasion,
The plurality of prepregs may be formed at the same position where the cuts are formed, or the cuts are intentionally slightly shifted, and the overlapping portions of the cut edges are shifted in the upper and lower prepregs, to reduce the thickness difference, and to reduce the step difference. Can be improved. At this time, the projections of the press die need to keep the cut positions and distances. Furthermore, it is also possible to simultaneously or separately mold prepregs made of different materials such as glass fibers, resin fibers, and metal fibers and integrally mold them.

As the prepreg, a sheet in which reinforcing fibers are arranged in one direction and impregnated with a matrix resin, for example, a unidirectional carbon fiber reinforced epoxy resin prepreg can be used. Furthermore, the unidirectional carbon fiber reinforced epoxy resin prepreg is used in the direction of 0 ° and 9 °.
It can be formed by laminating a plurality of layers so as to be in two directions of the 0 ° direction, adding a ± 45 ° direction thereto, or repeatedly laminating these. In that case,
Strength is obtained by the reinforcing fibers in other directions, and the strength is easily balanced.

Alternatively, for example, a bidirectional woven carbon fiber reinforced epoxy resin prepreg obtained by impregnating a matrix resin into a woven fabric using reinforcing fibers for warp and weft yarns can be used.

The production 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, as well as a fiber-reinforced composite material molded product having a hemispherical shape. The molded product is not limited to the final product.For example, a container-shaped preformed product is molded by the method of the present invention, and then the preformed products are combined in a molding die, and the 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 product according to the present invention is suitably applied to, for example, manufacturing of a three-dimensional helmet or a golf head.

Hereinafter, the present invention will be described with reference to specific examples and comparative examples. (Example) As a carbon fiber woven fabric reinforced epoxy resin prepreg, "Pyrofil TR350" manufactured by Mitsubishi Rayon Co., Ltd. was used.
H175S "(carbon fiber content 56% by volume) was used by laminating the fibers so that they were oriented at 0 ° and 90 °, and preform molding was performed in a hemispherical shape.

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 die 10 shown in FIG. 2, and the rectangular separating piece 1c is arranged along the hemispherical groove 10a, and the fan-shaped separating piece 1d is It is located on the fan-shaped projection 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 separation piece 1c are press-molded into a hemisphere and shaped. Before the press dies 10 and 11 were fitted, the prepreg was heated at 80 ° C. for 10 seconds with an infrared heater to soften the prepreg. Then, press mold 1
After cooling the inside of 0,11 by air blow at 20 ° C., the shape of the prepreg was fixed and the mold was released.

The removed prepreg was used in the third step shown in FIG.
On the hemispherical convex portion 20a of the press mold 20, the top of the convex portion 20a and the central region of the prepreg 1 are arranged together,
It is softened by heating at 80 ° C. for 10 seconds with an infrared heater, and is covered with a fourth press die 21 shown in FIG. 10 to bend the fan-shaped separating piece 1d into a hemispherical shape and adhere to the rectangular separating piece 1c.
Then, after cooling to 20 ° C. by air blow in a press mold, the prepreg shape was fixed and the mold was released to obtain a preform molded product.

This preform molded product was set in a mold, and bag molding was performed at a pressure of 4 kgf / cm ² ,
Curing was performed at 0 ° C. for 2 hours to obtain a molded product. A product excellent in strength and appearance and excellent in production stability could be obtained.

Comparative Example A circular prepreg 1 having a cut as shown in FIG. 1 was press-formed into a hemisphere at a time using only the press dies 20 and 21 shown in FIGS. 9 and 10. The molding was performed in the same manner as in the working example. As a result, the prepreg was drawn into the press mold, causing wrinkles and disorder of fibers, and a preform of sufficient quality could not be obtained.

As described above, according to the method for producing a fiber-reinforced composite material molded article of the present invention, even if it has a three-dimensional shape having a large curvature, it can be efficiently produced with uniform quality without wrinkles. It is possible to Further, the conventional manual lamination can be automated, and the quality stability and the production efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a prepreg suitably used in a production method of the present invention.

FIG. 2 is a schematic perspective view of a first press die suitably used in the first molding in the production method of the present invention.

FIG. 3 is a rear perspective view of a second press die corresponding to the first press die of FIG. 2;

FIG. 4 is an explanatory view showing a state at the time of first molding in the manufacturing method of the present invention.

FIG. 5 is an explanatory view showing a state at the time of a second molding in the manufacturing method of the present invention.

FIG. 6 is a plan view of another prepreg suitably used in the manufacturing 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 a conventional manufacturing method.

FIG. 9 is a schematic perspective view of a press die used in the conventional manufacturing method and preferably used in the second molding in the manufacturing method of the present invention.

FIG. 10 is a schematic perspective view of the back surface of the press die corresponding to the press die of FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 circular prepreg 1a central part 1b cut 1c rectangular separating piece 1d fan-shaped separating piece 2 circular prepreg 2a central part 2b notch 2c rectangular separating piece 2d fan-shaped separating piece 3 circular prepreg 3a central part 3b notch 4 circular notch 4a central notch DESCRIPTION OF SYMBOLS 10 1st press type | mold 10a Cross-shaped concave groove part 10b Sector-shaped protrusion 11 2nd press type | mold 11a Frame 11b Circular opening 11c Hemispherical cross-shaped part 20 3rd press type | mold 20a Hemispherical convex part 21 4th press type 21a Hemispherical concave part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Taku Ishimori 4-1-1 Ushikawadori, Toyohashi-shi, Aichi F-term (reference) 4F204 AA39 AB18 AB25 AD16 AM32 FA02 FA18 FB01 FB20 FF05 FG05 FG09 FJ30 FN02 FN11 FN17

Claims (6)

[Claims] 1. A two-dimensional notch or notch is formed in a fiber-reinforced resin prepreg cut into a predetermined shape, and adjacent edges of the notch or notch are overlapped with each other to form a three-dimensional shape. In the method of manufacturing a fiber-reinforced composite material molded product, a partly separated piece separated by the notch or notch is formed into a three-dimensional shape by press molding, and a part of the remaining part is overlapped with the partially separated piece by press molding, A method for producing a fiber-reinforced composite material molded article, wherein the whole is molded into a desired three-dimensional shape. 2. The method for producing a fiber-reinforced composite material molded product according to claim 1, further comprising positioning and setting the partial separation piece as a positioning piece at a predetermined portion of a press die. 3. The method for producing a fiber-reinforced composite material according to claim 1, wherein the prepreg is formed by using carbon fibers as reinforcing fibers and the carbon fibers are aligned in one direction. 4. The fiber reinforced composite according to claim 1, wherein a carbon fiber is used as a reinforcing fiber, and a prepreg which is a carbon fiber bidirectional woven fabric using said carbon fiber for a warp and a weft is used. Material manufacturing method. 5. The method for producing a fiber-reinforced composite material molded product according to claim 1, wherein a plurality of the prepregs are stacked and molded at the same time. 6. A molding apparatus for forming a fiber-reinforced composite material molded article having a three-dimensional shape, comprising a first and a second pair of press dies, wherein the first press die is a back-side three-dimensional molded article. The second press die has a projection on a part of the negative shape, and the second press die has a shape to be fitted to the projection on a part of the negative shape of the front surface side three-dimensional molded product. For molding fiber-reinforced composite materials.