JPS61114820A - Manufacture of plastic molded item - Google Patents

Abstract

PURPOSE:To make it possible to remove bubbles remaining in a fiber reinforced plastic, by placing in mating sections of molds a silicon rubber for preventing the fiber reinforced plastic from being squeezed out. CONSTITUTION:A mandrel 11 is held between recessed sections in top and bottom forces 6, and a cold-setting silicone rubber is injected via an injection port 12 and is set at normal temperatures. Then the mandrel 11 is removed from the recessed sections and the silicone rubber is taken out. An adhesive is applied to one of the recessed sections 9 and the silicone rubber is fitted thereto so that it is firmly to form a silicon rubber section 7 for preventing squeeze-out. The top and bottom forces are opened, a uncured laminate including a lightweight foamed member that is in the form of a ring and whose foaming has been suppressed and a fiber reinforced plastic 4 laminated thereon is set in the force and the forces are closed. As the silicone rubber is situated by the expansion pressure of the lightweight foamed member 3, the fiber reinforced plastic 4 will not be squeezed out.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing a plastic molded product in which a fiber-reinforced plastic is laminated and cured on the outer surface of a foamed member in which foaming is suppressed, particularly for cost-effective steering. The present invention relates to a method for manufacturing high quality plastic molded products such as fiber-reinforced plastic rims for wheels.

[Conventional technology]

Figure M5 is a front view of the light-discharge steering wheel.

FIG. 6 is a cross-sectional view taken along the line A-A, and in FIG. 2,
(l) is a rim part, (2) is a spoke part, (3) is a ring-shaped lightweight foam member made of a hard urethane foam material as an acid-resistant shape-retaining member for the rim part +1), and (4) is a lightweight foam member. It is reinforced with fibers such as glass fiber or carbon fiber laminated around the outer periphery of the member (3), and is made of fiber-reinforced plastic with a thermosetting resin such as epoxy resin as a matrix, and serves as a strength member for the rim portion (1).

(5) is the outer layer mold part. The above-mentioned lightweight steering wheel has a conventional rim part (1) core metal part and
Steering wheels whose spokes (2) are made of metal such as iron have a low natural frequency and poor running performance at high speeds.In order to improve operability, we designed a steering wheel that is lightweight without sacrificing rigidity. The rim part il+, which is farthest from the steering shaft axis and is most effective in increasing the number of unique shots, is made lighter.

Next, a conventional manufacturing method of the rim portion (1) will be explained.

The ring-shaped lightweight foam member (3) is molded by injecting hard urethane foam into a mold from a molding machine.Then, the outer surface of the lightweight foam member (3) is coated with epoxy to reinforcing fibers such as glass fiber or carbon fiber. Thermosetting resins such as resins and polyester resins are laminated in a wet state, defoamed, and placed in a mold to make the entire outer surface uniform, and then cured under pressure and heat. A thin film of strong fiber-reinforced plastic (4) is completely molded. Fiber-reinforced plastic (4) is not laminated in a wet state, but by pre-impregnating reinforcing fibers with resin, semi-hardened prepreg tape is laminated onto lightweight foam member (3) using a winding method, etc., and then placed in a mold. In some cases, it is hardened by applying pressure and heating.

The outermost molded part (5) is made of rubber, vinyl chloride resin, or the like by low pressure or flat pressure casting.

[Problem that the invention seeks to solve]

In the conventional manufacturing method as described above, when the fiber-reinforced plastic (4) is cured under pressure, the light sporadic pond member (3) has a low compressive strength, so sufficient pressure must be applied on the metal mold surface. However, there was a problem in that many air bubbles remained in the laminated fiber reinforced plastic (4), resulting in a significant decrease in strength. Also, if you try to increase the shape of the lightweight foam member (3) and apply pressure, only the upper and lower parts that are in contact with the mold will be pressurized, deforming the foam member (3) and changing the shape of the product after molding. The lightweight foam member (3) may be deformed, or the lightweight foam member (3) may be damaged, leaving a damaged part inside the ring body of the fiber-reinforced plastic (4), which has hardened and become stronger after molding, causing abnormal noises when vibrating. There was a problem. Furthermore, there is a problem that the fiber-reinforced plastic (4) protrudes from the mating part of the mold, and if this protruding part is cut to form a ring shape, the reinforcing fibers will be cut, resulting in a significant decrease in strength and product functionality. There was a problem with it disappearing.

The present invention was made to solve these problems, and involves heating and curing in a mold a covering made by coating a fiber-reinforced thermosetting plastic on the outer surface of a foamed member that suppresses foaming. The purpose of this invention is to prevent the extrusion of fiber-reinforced plastic that occurs at the mating parts of molds, and to obtain a method for manufacturing hard plastic molded products.

[Means for solving problems]

A method for manufacturing a plastic molded product according to the present invention.

In a product in which the outer surface of a foamed member with suppressed foaming is coated with fiber-reinforced thermosetting plastic and cured by heating in a mold, a silicone material is placed over the mating part of the mold to prevent the fiber-reinforced plastic from extruding. In addition to disposing rubber, the molding pressure of the covering body is generated by foaming the foam member when the covering body is heated and cured.

[For production]

In this invention, the extrusion-preventing silicone rubber prevents the extrusion of the fiber-reinforced plastic from the mating part of the mold, and by using a foam member that suppresses one foaming, the residual amount that was suppressed during heating is Re-foaming occurs and creates molding pressure.

Air bubbles remaining inside the fiber-reinforced plastic can be removed, resulting in a strong fiber-reinforced plastic.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a plan view of a mold according to an embodiment of the present invention, FIG. 2 is a BB-broken cross-sectional view thereof, FIG. 3 is a sectional view of the mold showing the molding state of the pressurizing part, and FIG. It is a sectional view of the mold showing the attachment state of the pressure part, and in Figure 1, (6) is a lightweight foam member (3).
Fiber-reinforced plastic in a wet or prepreg state laminated on the outer surface of the
(7) Room-temperature curing mold filled in a recess (9) provided across the mating surfaces of the upper and lower molds (6) so as to uniformly contact the outer surface of the Vi fiber-reinforced plastic (4). The extrusion prevention silicone rubber (RTV) section aI is a heating press section that presses and heats the upper and lower molds (6).

aυ is a ring-shaped core made of metal, for example, and has a diameter d2t- whose cross section is the same as the diameter d of the fiber-reinforced plastic (4) laminated on the rim part +1).

First, the silicone rubber (R'rV) part for preventing extrusion (
7) is formed by holding the core bar ri1) in the recesses of the upper and lower molds (6), and injecting silicone rubber that hardens at room temperature through the injection port Q3 provided in the mold (6). (RTV)
f: Inject and cure at room temperature. Next, the core metal aυ is taken out from the recess (9) and the cured silicone rubber is demolded. Apply adhesive to one side of the demolded recess (9) and insert the demolded silicone rubber (uTv) i.
As shown in the figure, form upper and lower extrusion prevention silicone rubber parts +7).

Fiber-reinforced plastic (4) laminated to the rim (1)
For pressure curing, use the above mold (6), open the upper and lower molds, and create a lightweight foam member with suppressed foaming in the shape of a square (
Set the uncured laminate of fiber reinforced plastic (4) on 3) and close the mold. Next, the upper and lower molds (6)
is pressed and heated by the heating press part Ql.

On the other hand, closed-cell foam is manufactured by press-fitting foamed materials such as urethane foam, polyethylene, polypropylene, polystyrene, vinyl chloride resin, urea resin, and phenolic resin into a mold cooled at a temperature ranging from room temperature to 0°C. have By using a lightweight foam material that suppresses foaming, fiber-reinforced plastic (4
) The bubbles remaining inside during wet molding and the bubbles between the prepreg layers are removed from the defoaming port a3 in the mold (6) by the molding pressure caused by the expansion and pressurization caused by the re-foaming of the remaining content that was suppressed from inside the mold (6). Defoaming. At this time, the degree of suppression of foaming before heating is t-il! By controlling the temperature and compression level, the expansion pressure during heating, that is, the molding pressure, can be adjusted as desired, and accordingly, the thickness of the fiber-reinforced plastic (4) to be molded can be changed as desired. In addition, due to the expansion pressure of the lightweight foam member (3), fiber-reinforced plastic (
When 4) is pressed into the concave part (9) of the mold (6), silicone rubber is placed at the mating part of the mold, so the fiber-reinforced plastic (4) does not protrude, and the protruding part is cut. It is possible to prevent a decrease in strength due to cutting of reinforcing transverse fibers.

〔Effect of the invention〕

As described above, according to the present invention, in the case where the outer surface of the foamed member with suppressed foaming is coated with Km fiber-reinforced thermosetting plastic, the covering is heated and cured in a mold, and the mating portion of the mold is In addition to disposing silicone rubber to prevent the fiber-reinforced plastic from extruding across the mold, the molding pressure for the covering is generated by foaming the foam member when the covering is heated and cured, so that the mating part of the mold is The protrusion of fiber-reinforced plastic is eliminated.

In addition, a method for manufacturing plastic molded products that can produce strong plastic molded products by re-foaming the foamed member whose foaming has been suppressed by heating and creating molding pressure to defoam the air bubbles in the fiber-reinforced plastic is obtained. It has the effect of being

[Brief explanation of the drawing]

FIG. 1 is a plan view of a mold according to an embodiment of the present invention;
Fig. 2 is a cross-sectional view taken along line B-Bi in Fig. 1, Fig. 3 is a partial cross-sectional view of gold showing the molded state of the silicone rubber part for preventing extrusion;
FIG. 4 is a partial sectional view of the mold showing the state in which the silicone rubber part for preventing extrusion is attached. Figure 5 is a front view of the lightweight steering wheel, and Figure 6 is A-A# of Figure 5! FIG. In the figure, (1) is the rim part, (2) is the spoke part, (
3) is a lightweight foam member, (4) is a Kasuri-woven reinforced plastic,
(5) is the outer mold part, (6) is the mold, (7) is the silicone rubber part for preventing extrusion, (8) is the mating surface of the mold, (
9) is a recess. (1G is a heated press part, aυ is a core metal, +13 is an injection port, and α4 is a defoaming port. In the drawings, the same reference numerals indicate the same - or equivalent parts.

Claims (3)

[Claims] (1) In a product in which the outer surface of a foamed member with suppressed foaming is coated with fiber-reinforced thermosetting plastic and cured by heating in a mold, the fiber-reinforced plastic is applied over the mating part of the mold. A method for manufacturing a plastic molded article, characterized in that a silicone rubber for preventing extrusion is provided, and the molding pressure of the covering is generated by foaming the foamed member when the covering is heated and cured. (2) Claim 1, characterized in that a foam member with closed cells prepared by press-fitting a foam material into a low-temperature mold below room temperature is used as the foam member with suppressed foaming.
2. Method for manufacturing plastic molded products described in Section 1. (3) The fiber-reinforced thermosetting plastic is reinforced with one type of glass fiber or carbon fiber, and has an epoxy resin as a matrix, as described in claim 1 or 2. A method for manufacturing plastic molded products.