JP3010704B2 - Molding method of fiber reinforced resin molded product - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for molding a fiber-reinforced resin molded product, particularly a fiber-reinforced resin molded product having a folded portion.

[Conventional technology]

Recently, FR has come into practical use as a car outer panel
In P (glass fiber reinforced thermosetting resin) products, as shown in FIG.
With Wb, an undercut portion (hereinafter referred to as a folded portion) like Wc must be formed. In order to form the folded portion Wc, as shown in FIG. 5, when forming the molded product W by forming the cavity 6 between the upper die 4 and the lower die 3, the molded product W is die-cut. It is necessary to provide the lower mold 3 with the movable part 3A. The present applicant has previously filed an application for the registration of a utility model for such a plastic molding die (Japanese Utility Model Application Laid-open No. 64-9715).
Reference).

As shown in FIG. 6, a mold for forming a product having a folded portion needs to have a movable portion 4a on the upper die 4 and a movable portion 3a on the lower die 3. The movable portion 3a must be movable in the direction of the solid arrow along the inclined sliding portion 7 for sliding in the tangential direction of the folded portion of the molded product W shown by the broken line.

In the case of using a mat of preformed reinforcing fibers (preform type), integral since molding becomes difficult to divide the reinforcing fiber mat as shown in FIG. 7 to W ₁ and W ₂ It is used in combination later.

[Problems to be solved by the invention]

When a product having a folded portion is molded by a mold, it is necessary to provide a movable portion in the mold as described above, so the molding mold is expensive, and also, a fixed portion and a movable portion of the mold are required. During this time, liquid resin enters the molded product, causing burrs on the molded product, and furthermore, the movable part of the mold does not move or the life of the mold is shortened.

The use of a mat of preformed reinforcing fibers or the like in combination afterwards is a complicated operation requiring the precision of superposing and combining the reinforcing fibers, which is troublesome and inefficient. In addition, if the combination accuracy is poor, it causes deterioration of the surface quality of the molded product.

The present invention solves the above-mentioned problem, and eliminates the need to provide a movable portion in a resin molding die by maintaining the outer shape of a required shape portion of a molded product as it is, and changing the outer shape using a core material for a folded portion. It is another object of the present invention to provide a method for molding a fiber-reinforced resin molded article which improves the surface quality of the molded article.

[Means and Actions for Solving the Problems]

In the present invention, the tip of the reinforcing fiber is folded to form a folded portion, the core-attached reinforcing fiber having a core attached to the inside of the folded portion is previously formed, and the core-attached reinforcing fiber is vertically moved. This is a method in which a fiber-reinforced resin molded product is molded by placing the mold in a cavity formed between the molds, clamping the mold, and then injecting a resin.

The folded part of the molded product is wrapped with a core material with two layers of reinforcing fibers, or is bonded to a single-layer reinforcing fiber to form a reinforcing fiber in a shape in which the folded part is eliminated, and this molded reinforcement is formed. When the fiber for molding is put into a usual mold for compression molding and resin is injected to form a fiber-reinforced resin molded product, since the molded product has no folded portion, it can be easily die-cut.

〔Example〕

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

FIG. 1 is a cross-sectional view of a molding die. In a cavity formed between a lower die 3 and an upper die 4, a folded portion is provided with a reinforcing fiber 1 around a core material 2. The outer shape is not a folded portion, and the molded product can be die-cut without providing a movable portion in the lower die 3 or the upper die 4.

In FIG. 1, the reinforcing fiber 1 having the outer shape with the folded portion removed by attaching the reinforcing fiber around the core material 2 is put into a mold and clamped, and the resin is injected from the injection port 5 to reinforce the resin. At the same time, the resin layer is formed around the reinforcing fiber 1 to form a fiber-reinforced resin molded article. As the reinforcing fiber 1, it is preferable to use glass fiber. Since this fiber-reinforced resin molded article has no folded portion, it can be easily removed from the mold.

Next, a structure and a method for attaching the reinforcing fiber 1 around the core material 2 will be described.

FIG. 2 shows a structure in which the core material 2 is wrapped around the reinforcing fiber 1 as two inner and outer layers. In FIG. 2 (A), between the outer layer 1A of the reinforcing fiber 1 and the tip of the inner layer 1E. Put the core material 2 formed in advance, hold the core material 2 by bending the inner layer 1E first,
Next, the outer layer 1A is folded outside.

In FIG. 2 (B), the tip of the inner layer 1F is folded back to hold the core material 2 at that portion, and the inner layer 1F is held by the outer peripheral surface of the tip of the outer layer 1B.
It is superimposed.

In FIG. 2 (C), the outer layer 1D and the inner layer 1H have a structure in which the inner layer 1H is abutted on the bottom, and the outer layer and the inner layer may be reversed.

Next, a structure and a method for attaching the single-layer reinforcing fiber 1 around the core material 2 will be described.

FIG. 3 (A) shows the core material 2 wrapped with a single-layer reinforcing fiber 1a, and in FIGS. 3 (B) and (C), the inside of the single-layer reinforcing fiber 1b, 1c is shown. The core material 2 is attached by bonding.

The folded portion is not limited to the shape of the embodiment, but can be applied to a molded product of a folded portion having another shape by setting the core material to a required shape specification.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION This invention eliminates the necessity to provide a movable part in the metal mold | die for molding of the fiber reinforced resin molded article which has a folded part, and has the effect that a molded article with good surface quality can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molding die used in the present invention, FIGS. 2 (A) to 2 (C) are sectional views of an embodiment of the present invention, and FIGS. 3 (A) to 3 (C) are respectively FIG. 4 is a cross-sectional view of a molded article, FIGS. 5 and 6 are cross-sectional views of a conventional molding die, and FIG. 7 is a conventional molding of reinforcing fibers. FIG. 1: fiber for reinforcement, 1A, 1C, 1D: outer layer 1E, 1G, 1H: inner layer, 1a, 1b, 1c: single layer 2: core material, 3: lower mold 4: upper mold, 5: resin inlet W: Molded product, Wa: shaped part Wb: shaped part, Wc: folded part

Claims (1)

(57) [Claims] The present invention relates to a reinforcing fiber with a core, in which a tip portion of the reinforcing fiber is folded to form a folded portion, and a reinforcing material having a core attached to the inside of the folded portion is formed in advance. A method for molding a fiber-reinforced resin molded product, comprising: placing the molded product in a cavity formed between upper and lower molds, clamping the mold, and then injecting a resin to mold the fiber-reinforced resin molded product.