JP6587771B1 - Press molding apparatus and press molding method for a fiber reinforced composite material molded article. - Google Patents

Abstract

The present invention relates to a press molding apparatus for producing a highly productive fiber-reinforced composite material molded article without limiting the resin composition of the prepreg and without lowering the quality and work efficiency, and the press molding apparatus. A press forming method is provided. A concave upper mold disposed above, a convex lower mold paired with the upper mold, and a periphery of the lower mold, the prepreg being stably disposed And a wrinkle restraining plate that suppresses the occurrence of wrinkles in the fiber-reinforced composite material molded product, and the lower mold includes a step around the bottom dead center of the upper mold, The wrinkle restraining plate has an inclined portion that gradually spreads outward at an angle θ equal to or larger than the draft formed above, and the wrinkle restraining plate has an inner wall facing the lower mold. When the mold has reached the bottom dead center, the mold is disposed so as to be in close contact with the inclined portion, and resin dripping between the lower mold and the wrinkle restraining plate is suppressed. [Selection] Figure 1

Description

  The present invention relates to a press molding apparatus for manufacturing a fiber reinforced composite material molded product from a prepreg and a press molding method for manufacturing a fiber reinforced composite material molded product.

In recent years, due to environmental problems, efforts are being made to improve fuel efficiency in the automobile industry, the aviation industry, and the like. Among them, in order to reduce the weight of the vehicle body and the airframe, replacement of metal with fiber reinforced resin is expected, and attention is focused on fiber reinforced composite materials using resin.
Resins used for fiber reinforced composite materials are thermoplastic resins and thermosetting resins, and fiber reinforced composite materials that reinforce fibers with these resins, unlike metals, can be molded and shaped by heating, resulting in high production. It is widely used in various fields because of its characteristics such as being easy to perform secondary processing such as welding, electrical insulation, corrosion resistance, and excellent recyclability.
In addition, carbon fiber reinforced composite materials using carbon fiber as the fiber are lightweight, high strength and high rigidity, so the above-mentioned automobile industry, aviation industry, ship industry, space field, wind power generation and sporting goods. Have been used in a wide range of fields.

Molded products using fiber-reinforced composite materials are made of epoxy, phenol, polyester, and other thermosetting resins that are made by mixing additives such as hardeners and adhesives with fibrous reinforcements such as glass cloth and carbon fibers. A prepreg that has been impregnated and heated or dried to a semi-cured state is cured by heating and pressing to produce.
Processing of carbon fiber reinforced composite materials includes autoclave molding, oven molding, press molding, RTM / VaRTM method, pultrusion molding, filament wiping, sheet winding, etc. Among them, high productivity and high quality fiber reinforced composite From the viewpoint of obtaining a molded material, press molding is considered desirable.

FIG. 7 is an explanatory diagram for simply explaining a conventional method for forming a fiber-reinforced composite material molded article by press molding using a prepreg.
The pressing device includes a concave upper mold 110 disposed above, a convex lower mold 120 that forms a pair with the upper mold 110, and a wrinkle suppression plate 130 provided around the lower mold 120. The prepreg 200 is disposed on the upper surface of the lower mold 120 (a).
Then, the upper mold 110 is lowered toward the lower mold 120, the end of the prepreg 200 is sandwiched between the upper mold 110 and the wrinkle restraining plate 130 (b), and the upper mold 110 is further lowered. (C) Pressurize the prepreg 200 disposed between the upper and lower molds (d), raise the upper mold 110 after the pressurizing step (e), and take out the molded product (f).

  The above press molding has a simple molding process, does not require expensive capital investment like autoclave molding, and can produce high-quality molded products with a short molding time. It can be said that this is an important molding method for reducing the price without degrading the quality.

However, the prepreg used in press molding is in a semi-cured state, and the resin viscosity may be lowered by heating, and the resin composition may sag. Therefore, there is a problem that the resin composition of the prepreg hangs down in the gap of the press device and causes a malfunction of the mold.
FIG. 8A is a detailed explanatory view of an example of the prepreg resin dripping that occurs in the pressurizing step of FIG. 7D, but the resin composition of the pressed prepreg 200 is used as the lower mold 120 to suppress wrinkles. A state of drooping in the gap of the plate 130 is shown. Moreover, FIG.8 (b) has shown the example of the resin dripping at the time of the pressurization process of another molded article. In this way, the resin dripping into the gap of the press device occurs regardless of the shape of the molded product.
Such resin sagging may cause resin shortage and burrs in the molded product, and may deteriorate the quality of the molded product, and the sagging resin composition flows into the gap in the press device and is removed. Work is required and hinders productivity improvement.

  As a method for adjusting the fluidity of the resin composition of the prepreg with respect to such a problem, Patent Document 1 discloses that “a mixed epoxy of 50 to 90 parts by weight of a solid epoxy resin and 10 to 50 parts by weight of a liquid epoxy resin” Resin, rubber, and a curing agent. The rubber is blended in an amount of 5 to 60 parts by weight with respect to 100 parts by weight of the mixed epoxy resin, and the curing agent is 1 to 1 part with respect to 100 parts by weight of the mixed epoxy resin. A resin composition for a prepreg ”(100 parts by weight) is disclosed (Patent Document 1: Japanese Patent Application Laid-Open No. 2005-213352).

  Patent Document 2 states that “a prepreg using an epoxy resin composition that is excellent in storage stability at room temperature, can be cured by heating at a relatively low temperature and in a short time, and the cured resin has high heat resistance, heating. A prepreg comprising a reinforcing fiber and an epoxy resin composition suitable for press molding, particularly high cycle press molding, is disclosed (Patent Document 2: Patent No. 2). No. 5682837).

JP 2005-213352 A Japanese Patent No. 5682837

The prepregs disclosed in Patent Document 1 and Patent Document 2 described above are intended to adjust the fluidity of the resin by the configuration of the resin composition of the prepreg, and of course only in the case of a resin composition having a disclosed configuration. The effect is demonstrated. That is, the problem is not solved for prepregs using resin compositions other than those described above. In recent years, fiber reinforced composite materials used in various fields are not necessarily limited to the above-mentioned limited resin compositions due to their use, shape, size, required cost, etc., and increase. It is difficult to apply to all press forming corresponding to the needs.
Accordingly, the present invention provides a press molding apparatus for manufacturing a highly productive fiber-reinforced composite material molded article without limiting the resin composition of the prepreg and without reducing the quality and work efficiency, and the press molding apparatus. It aims at providing the press molding method using.

As a result of intensive studies, the present inventors have found a press-molding apparatus for a fiber-reinforced composite material molded product that suppresses resin dripping of the resin composition of the prepreg. This is shown below. In addition, in this item, in order to make an understanding of this invention easy, the code | symbol in the Example corresponding to each component requirement is attached.
(1) A press molding apparatus 1 for producing a fiber-reinforced composite material molded product 20 by press-molding a prepreg 2, which is a concave upper mold 11 disposed above and a pair with the upper mold. And a wrinkle suppressing plate 13 that is provided around the lower mold 12 and that stably disposes the prepreg 2 and suppresses the generation of wrinkles in the fiber-reinforced composite material molded product. The lower mold 12 includes a step a that circulates in the vicinity of the bottom dead center of the upper mold 11, and the lower portion of the step a is equal to or more than the draft 121 formed above the step a. The wrinkle restraining plate 13 has an inner wall 131 facing the lower mold 12 and the upper mold 11 has reached the bottom dead center. Then, it is arranged so as to be in close contact with the inclined portion 122, and the Press-forming apparatus characterized by inhibiting the resin sagging between the die 12 and the blank holder plate 13.
(2) In the above (1), the angle θ of the inclined portion 122 provided in the lower mold 12 is set to 1 to 15 ° with respect to the center line of the lower mold 12. The press molding apparatus as described.

(3) The concave upper mold 11 disposed above, the convex lower mold 12 paired with the upper mold, and the prepreg 2 provided around the lower mold 12 are stably provided. A press-molding method for producing a fiber-reinforced composite material molded product by press-molding the prepreg 2, comprising a wrinkle restraining plate 13 that is disposed and suppresses the generation of wrinkles in the fiber-reinforced composite material molded product,
The step of disposing the prepreg 2 between the upper mold 11 and the lower mold 12, and the upper mold 11 is lowered toward the lower mold 12 to pressurize the prepreg 2 disposed between the upper and lower molds. A pressurizing step and a step of raising the upper mold 11 after the pressurizing step and taking out the molded product 20;
The lower mold 12 has a step a that circulates in the vicinity of the bottom dead center of the upper mold 11, and the lower portion of the step a is at an angle θ that is equal to or greater than the draft 121 formed above the step a. The inner wall 131 facing the lower mold 12 of the wrinkle restraining plate 13 has an inclined portion 122 that gradually spreads outward, and reaches the bottom dead center associated with the lowering of the upper mold 11. A press molding method characterized by suppressing resin dripping between the lower mold 12 and the wrinkle restraining plate 13 by being brought into close contact with the inclined portion 122.

  According to the press molding apparatus and press molding method for a fiber reinforced composite material molded product of the present invention, high-productivity fiber reinforced composite material molding without limiting the resin composition of the prepreg and without reducing the quality and work efficiency. Product can be manufactured. In addition, since resin dripping can be suppressed, there is no need to remove the dripping resin, and continuous press molding is possible, which is suitable for mass production.

It is sectional drawing for description of the press molding apparatus of the fiber reinforced composite material molded product concerning this invention. It is a perspective view for description of the press molding apparatus of the fiber reinforced composite material molded product according to the present invention. It is sectional drawing for description of an effect | action in one Example of the press molding apparatus of the fiber reinforced composite material molded product concerning this invention. It is sectional drawing for description of an effect | action in the other Example of the press molding apparatus of the fiber reinforced composite material molded product concerning this invention. It is a manufacturing-process figure in one Example of the press molding method concerning this invention. It is a manufacturing-process figure in the other Example of the press molding method concerning this invention. It is explanatory drawing of the shaping | molding method of the fiber reinforced composite material molded article by the press molding using the prepreg performed conventionally. It is a detailed explanatory view of resin sag of prepreg.

The form for implementing this invention is demonstrated in detail based on the figure of an Example. It should be noted that the present invention is not limited to the embodiments, and the design can be changed as appropriate within a range well known to those skilled in the art.
In the present specification, the fiber-reinforced composite material molded product is obtained by press-molding a prepreg obtained by impregnating and drying a fiber bundle, for example, a fiber bundle such as carbon fiber or crow fiber, with a thermoplastic resin or a thermosetting resin. And a fiber-reinforced resin composite material / metal integrated molded product in which the prepreg and a metal such as aluminum, iron, and titanium are joined by heating and pressurizing. The fiber-reinforced composite material molded product is obtained by molding a fiber-reinforced composite material according to the application and shape.
In the present invention, a thermosetting resin, a thermoplastic resin, and a resin composition containing one of them can be used.
Examples of the resin constituting the prepreg include an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, a polyurethane resin, and a phenol resin as thermosetting resins, and these resins can also be used in combination.
Examples of the thermoplastic resin include acrylic resin, polyester resin, polycarbonate resin, polypropylene resin, polyethylene resin, polystyrene resin, vinyl chloride resin, and polyamide resin. These may be used singly or in combination.

  In the figure, 1 is a press molding apparatus, 11 is an upper mold, 12 is a lower mold, 121 is a draft, 122 is an inclined portion, 13 is a wrinkle restraining plate, 131 is an inner wall, 2 is a prepreg, and 20 is a fiber reinforced composite. It is a material molded product (also simply called a molded product).

[Press forming equipment for fiber reinforced composite material molded products]
The fiber-reinforced composite material molded product press molding apparatus 1 according to the present invention is a device for producing a fiber-reinforced composite material molded product 20 by press-molding a prepreg 2, as shown in FIGS. 1 and 2. A concave upper mold 11 to be disposed, a convex lower mold 12 that forms a pair with the upper mold 11, and a periphery of the lower mold 12, and the prepreg 2 is stably disposed. At the same time, it is composed of a wrinkle suppression plate 13 that suppresses the generation of wrinkles in the fiber-reinforced composite material molded product 20.
The concave shape of the upper mold 11 is a female mold for pressing to mold the shape of the molded product, and the convex shape of the lower mold 12 is a male mold for the upper mold 11, and the shape of the molded product to be molded It is formed according to.

The lower mold 12 in the press molding apparatus 1 according to the present invention includes a step a at a position around the bottom dead center of the upper mold 11. Here, the bottom dead center is a position where the slide position of the press device is the lowest during press molding, and the bottom dead center is the lowest position where the upper mold 11 is lowered toward the lower mold 12. The lower mold 12 is provided with a step a in its vicinity including the position corresponding to the position of the bottom dead center which is the lowest position of the upper mold 11 as it goes around.
The step a provided in the lower mold 12 is provided by forming an inclined portion 122 whose lower portion gradually spreads outward at an angle θ equal to or greater than the draft 121 formed above the lower die 12. . The draft 121 is an inclination provided in the mold in order to smoothly remove the molded product from the mold. In order to minimize the wear of the mold and make it easy to take out a molded product from the mold, the draft 121 is generally inclined at about 0.1 to 3 ° in consideration of balance, size, and resin characteristics. However, in the present invention, since the draft angle 121 can be implemented substantially even at 0 °, 0 ° is also included.
Therefore, as shown in FIG. 2A, the lower mold 12 is inclined so that it gradually spreads outward at an angle θ equal to or larger than the draft 121, below the draft 121. Since 122 is formed, a step a is formed at the boundary between the draft 121 and the inclined portion 122.

In the embodiment shown in FIG. 1, the angle θ of the inclined portion 122 is set to 1 to 15 ° with respect to the center line of the lower mold, and the step a is formed in consideration of the angle of the draft 121. It has been adjusted so that. For example, if the draft 121 is 1 ° with respect to the center line of the lower mold, the inclined portion 122 is set to 3 ° to form the step a.

In the embodiment shown in FIG. 2, as shown in FIG. 2 (b), the position of the step a is formed so as to substantially coincide with the position around the bottom dead center of the upper mold 11.
The position of the step a may be formed near the bottom dead center, that is, slightly below the position around the bottom dead center, depending on the structure of the molded product to be press-molded. In the present invention, the position of the step a is set so that an edge b of a wrinkle restraining plate 13 to be described later is in contact with an inclined portion 122 extending downward from the step a and matches the shape of the molded product to be press-molded. An inner wall 131 extending downward from the edge b is provided at a position adjusted so as to be in close contact with the inclined portion 122 of the lower mold 12.
Therefore, in the present invention, the position of the step a is adjusted according to the shape of the molded product to be press-molded, particularly the thickness, so that the step a is formed at the position, and the lap around the position of the bottom dead center. In some cases, it may be formed so as to rotate around a position near the bottom dead center below the bottom dead center.
For example, in FIG. 1A, the step a is formed at a position that goes around the bottom dead center. On the other hand, in the embodiment shown in FIG. 1B, the level difference a is formed near the bottom dead center at a position lower by the thickness of the molded product.

The wrinkle restraining plate 13 in the press molding apparatus for a fiber reinforced composite material molded product according to the present invention is such that the inner wall 131 facing the lower mold 12 is inclined when the upper mold 11 reaches the bottom dead center. It arrange | positions so that the part 122 may be closely contacted.
That is, when the upper die 11 is lowered during pressing and the wrinkle restraining plate 13 is pressed down to reach the bottom dead center, the inner wall 131 on the lower die 12 side of the pushed wrinkle restraining plate 13 is moved to the lower die. The inner wall 131 of the wrinkle restraining plate 13 is formed so as to be in contact with the inclined portion 122 provided in the mold 12.

FIG. 3 is a simplified illustration for explaining an example of the operation of the press-molding apparatus for the fiber-reinforced composite material molded product according to the present invention. As shown in FIG. The prepreg 2 is lowered while being pressed between the prepreg 2 and the prepreg 2 and is further pressed as shown in FIG. 3B. When the upper die 11 reaches the bottom dead center, the crease suppressing plate 13 is pressed. The edge b contacts the inclined portion 122 extending downward from the step a. At the same time, the inner wall 131 extending downward from the edge b of the wrinkle suppression plate 13 is also in close contact with the inclined portion 122 of the lower mold 12.
Thus, the gap between the lower mold 12 and the wrinkle restraining plate 13 approaches zero as much as possible, and the resin is prevented from dripping from the prepreg 2.

  FIG. 4 shows the operation of another embodiment of the press-molding apparatus for the fiber-reinforced composite material molded product according to the present invention explained in FIG. 3, but FIG. In (a), the upper die 11 is lowered while being pressed while the prepreg 2 is sandwiched between the wrinkle restraining plates 13, and is further pressurized as shown in FIG. 4 (b). In the embodiment shown in FIG. 4, the bottom dead center is positioned above the step a by the thickness of the molded product. When the upper mold 11 reaches the bottom dead center, the configuration in which the edge b of the wrinkle restraining plate 13 is in contact with the inclined portion 122 extending downward from the step a is the same as the embodiment shown in FIG. At the same time, the inner wall 131 extending downward from the edge b of the wrinkle suppression plate 13 is also in close contact with the inclined portion 122 of the lower mold 12, and the gap between the lower mold 12 and the wrinkle suppression plate 13 regardless of the shape of the molded product. Suppresses the resin from dripping from the prepreg 2 as close to zero as possible.

[Press molding method]
Below, the press molding method using the press molding apparatus of the fiber reinforced composite material molded article concerning this invention is demonstrated.
The press molding method according to the present invention is performed by press molding.
Press molding is a molding method in which a material is deformed and molded by sandwiching the material with a plurality of (for example, two) molds (for example, an upper mold and a lower mold), and heating and pressurizing the material.

In the present invention, as shown in the manufacturing process diagram of FIG. 5, a concave upper mold 11 disposed above, a convex lower mold 12 paired with the upper mold 11, and the lower The prepreg 2 is disposed on the upper surface of the lower mold 12 of the press molding apparatus 1 provided with a wrinkle restraining plate 13 around the mold 12, and the prepreg is disposed between the upper mold and the lower mold ( a process). By sandwiching and pressing the prepreg 2 between the concave upper mold 11 and the convex lower mold 12, the fiber reinforced resin composite material molded product 20 can be formed into a three-dimensional shape.
In the present embodiment, the wrinkle restraining plate 13 applies a wrinkle restraining force by a gas spring. And the edge part of the prepreg 2 is arrange | positioned on the upper surface of the wrinkle suppression board 13. As shown in FIG.
In the present embodiment, the prepreg 2 uses a fiber reinforced resin prepreg obtained by impregnating carbon fiber with an epoxy resin, but is not particularly limited.

In the embodiment shown in FIG. 5, the lower mold 12 constituting the press molding apparatus 1 includes a step a at a position around the bottom dead center of the upper mold 11. It has an inclined portion 122 that gradually spreads outward at an angle θ equal to or greater than the draft angle 121 formed above. The wrinkle restraining plate 13 is configured such that the inner wall 131 facing the lower mold 12 is in close contact with the inclined portion 122 when the upper mold 11 reaches the bottom dead center.
Then, the upper mold 11 is lowered toward the lower mold 12 (step b), the end of the prepreg 2 is held between the upper mold 11 and the wrinkle restraining plate 13, and the upper mold 11 is further lowered. And pressurizing (step c).

When the pressure is further increased to the bottom dead center, an edge b which becomes a side connecting the upper surface of the wrinkle restraining plate 13 and the inner wall 131 is formed on the upper end portion of the inclined portion 122 formed below the step a of the lower mold 12. Touch.
At the same time, the inner wall 131 of the wrinkle restraining plate 13 formed so as to correspond to the inclined portion 122 of the lower mold 12 is in contact with the inclined portion 122 of the lower mold 12. In this way, the edge b of the wrinkle restraining plate 13 is configured to contact the inclined portion 22 of the lower mold 12, and the inner wall of the wrinkle restraining plate 13 and the inclined portion 122 of the lower mold 12 are closely contacted without any gaps, Resin dripping between the lower mold and the wrinkle suppression plate is suppressed (step d).
Thereafter, after the pressurizing step, the upper mold 11 is raised (step e), and the molded product 20 is taken out (step f).

  The manufacturing process diagram of FIG. 6 is a case of a molded product of another shape, and the lower mold 12 constituting the press molding apparatus 1 is near the bottom dead center of the upper mold 11. A step a is provided at a position that circulates slightly below the position that circulates the dead point, and the lower portion of the step a is directed outward at an angle θ that is equal to or greater than the draft angle 121 formed above the step a. It has the inclined part 122 which spreads gradually. Further, the wrinkle suppression plate 13 is configured such that the inner wall 131 facing the lower mold 12 is in close contact with the inclined portion 122 in a state where the upper mold 11 has reached the bottom dead center.

Also in the embodiment shown in FIG. 6, the manufacturing process is the same as the manufacturing process described in FIG. 5. When the upper mold 11 is pressurized to the bottom dead center, the upper surface of the wrinkle restraining plate 13 and the inner wall 131 are connected. The edge b which becomes a side is in contact with the upper end portion of the inclined portion 122 formed below the step a of the lower mold 12.
At the same time, the inner wall 131 of the wrinkle restraining plate 13 formed so as to correspond to the inclined portion 122 of the lower mold 12 is in contact with the inclined portion 122 of the lower mold 12, and the edge b of the wrinkle restraining plate 13 is the lower mold. The inner wall of the wrinkle restraining plate 13 and the slanted portion 122 of the lower mold 12 are in close contact with each other without any gap, and the resin dripping between the lower mold and the wrinkle restraining plate is suppressed. (Step d).

The press molding apparatus and press molding method for a fiber reinforced composite material molded article is provided with the inclined portion 122 in the lower mold 12 and the wrinkle restraining plate 13 having a shape corresponding thereto. Resin dripping of the prepreg 2 from the gap between the restraining plates 3 can be suppressed, and a highly productive fiber-reinforced composite material molded product 20 can be manufactured without lowering the quality and work efficiency.
Moreover, since the press molding apparatus 1 of the present invention structurally suppresses resin sag, it is not necessary to limit the resin constituting the prepreg 2 and can cope with the prepreg 2 of any resin composition.

1: Press molding device 11: Upper mold 12: Lower mold 121: Draft 122: Inclined portion 13: Wrinkle restraining plate 131: Inner wall 2: Prepreg 20: Fiber reinforced composite material molded product 110: Upper mold 120: Lower Mold 130: Wrinkle suppression plate 200: Prepreg

Claims (2)

A press molding apparatus for producing a fiber-reinforced composite material molded product by press molding a prepreg,
A concave upper mold disposed above;
A convex lower mold paired with the upper mold;
It is provided around the lower mold, and comprises a wrinkle suppressing plate that stably arranges the prepreg and suppresses the occurrence of wrinkles of the fiber-reinforced composite material molded product,
The lower mold includes a step around the bottom dead center of the upper mold, and the lower part of the lower mold gradually outwards at an angle θ equal to or larger than the draft formed above the lower mold. Has an expanding slope,
The wrinkle restraining plate is disposed so that the inner wall facing the lower mold is in close contact with the inclined portion when the upper mold reaches the bottom dead center,
Resin dripping between the lower mold and the wrinkle restraining plate is suppressed, and the angle θ of the inclined portion provided in the lower mold is 1 with respect to the center line of the lower mold. Press forming apparatus set at ˜15 ° . A fiber-reinforced composite material that stably arranges a concave upper mold disposed above, a convex lower mold that forms a pair with the upper mold, and a prepreg provided around the lower mold A press-molding method for producing the fiber-reinforced composite material molded product by press-molding the prepreg, comprising a wrinkle-reducing plate that suppresses the occurrence of wrinkles in the molded product,
Placing the prepreg between an upper mold and a lower mold;
A pressurizing step of lowering the upper mold toward the lower mold and pressurizing the prepreg disposed between the upper and lower molds;
It consists of a step of raising the upper mold after the pressurizing step and taking out the molded product,
The lower die has a step around the bottom dead center of the upper die, and the lower part of the lower die is directed outward at an angle θ equal to or larger than the draft formed above the lower die. The inner wall of the wrinkle restraining plate facing the lower mold has an inclined part that gradually spreads, and is brought into close contact with the inclined part in a state of reaching the bottom dead center associated with the lowering of the upper mold. Resin dripping between the mold and the wrinkle suppression plate is suppressed, and the angle θ of the inclined portion provided in the lower mold is 1 to 15 ° with respect to the center line of the lower mold. The press molding method set to.