JPH0244692B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing a plastic molded product in which fiber-reinforced plastic is laminated and cured on the outer surface of a foamed member in which foaming is suppressed, and in particular to a lightweight steering wheel. The present invention relates to a method of manufacturing a plastic molded product suitable for a fiber-reinforced plastic rim of a wheel.

[Conventional technology]

FIG. 5 is a front view of the lightweight steering wheel, and FIG. 6 is a cross-sectional view taken along the line A-A. A ring-shaped lightweight foam member made of hard urethane foam material, etc.
4 is a fiber-reinforced plastic layered around the outer periphery of the lightweight foam member 3, reinforced with fibers such as glass fiber or carbon fiber, and made of a thermosetting resin such as epoxy resin as a matrix, and serves as a strength member of the rim portion 1. 5 is an outer layer mold part. The above-mentioned lightweight steering wheel is difficult to operate because the conventional steering wheel in which the core metal part and the spoke part of the rim part 1 are made of metal such as iron has a low natural frequency and poor running performance at high speeds. In order to improve this, the rim part 1, which is farthest from the steering shaft axis and most effective in increasing the natural frequency, has been made lighter to increase the natural frequency without reducing rigidity.

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 foaming machine, and then the outer surface of the lightweight foam member 3 is coated with reinforcing fibers such as glass fiber or carbon fiber, epoxy resin, polyester resin, etc. The thermosetting resin is impregnated and degassed in a wet state and then laminated, placed in a mold to make the entire outer surface uniform in thickness, and cured by applying pressure and heating to create a thin film with high strength. A fiber-reinforced plastic 4 is molded. Fiber reinforced plastic 4 is
Rather than laminating in a wet state, the reinforcing fibers are pre-impregnated with resin and semi-cured prepreg tape is laminated on the lightweight foam member 3 using a winding method, etc., and then placed in a mold and cured by applying pressure and heating. In some cases, it may be possible to do so. Outermost layer outer mold part 5
is molded from rubber, vinyl chloride resin, etc. by low-pressure or high-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 lightweight foam member 3 has a low compressive strength, so sufficient pressure cannot be applied to the metal mold surface, and the fiber-reinforced plastic There was a problem in that many air bubbles remained in the laminated plastic 4, resulting in a significant decrease in strength. In addition, 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 lightweight foam member 3, and the product shape after molding may be deformed. There was a problem in that the foamed member 3 was damaged, and the damaged part remained in the ring body of the fiber-reinforced plastic 4, which had become strong through hardening after molding, causing abnormal noise during vibration. Furthermore, there is the 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 are cut, resulting in a significant decrease in strength and the loss of product functionality. The dot was hot.

The present invention has been made to solve such problems, and includes heating and curing in a mold a coating in which a fiber-reinforced thermosetting plastic is coated on the outer surface of a foam member whose foaming is suppressed. The purpose of this invention is to prevent the extrusion of fiber-reinforced plastic that occurs at the mating parts of molds, and to provide a method for manufacturing strong plastic molded products.

[Means for solving problems]

The method for manufacturing a plastic molded article of this invention includes:
In the case where the outer surface of a foamed member with suppressed foaming is coated with fiber-reinforced thermosetting plastic and cured by heating in a mold, it is used to prevent the fiber-reinforced plastic from extruding across the mating part of the mold. In addition to disposing silicone rubber, the molding pressure of the covering body is generated by foaming the foam member when the covering body is heated and cured.

[Effect]

In this invention, the extrusion-preventing silicone rubber prevents the fiber-reinforced plastic from extruding from the mating part of the mold, and by using a foam member with suppressed foaming, the remaining amount that was suppressed during heating is Re-foaming occurs and molding pressure is applied, allowing air bubbles remaining inside the fiber-reinforced plastic to be defoamed, resulting in a strong fiber-reinforced plastic.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 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 the line B-B, FIG. 3 is a cross-sectional view of the mold showing the molding state of the pressurizing part, and FIG. is a cross-sectional view of the mold showing the mounting state of the pressurizing part, and in the figure, 6 is a line for pressure-curing the fiber-reinforced plastic 4 in the state of wet or prepreg laminated on the outer surface of the lightweight foam member 3. A mold made of a material with a small expansion coefficient, for example, steel, is filled into a recess 9 provided on the mating surface side of the upper and lower molds 6 so as to uniformly contact the outer surface of the fiber-reinforced plastic 4. The extrusion prevention silicone rubber part 10 of the room temperature curing type is a heating press part that presses and heats the upper and lower molds 6. Reference numeral 11 is a ring-shaped core made of metal, for example, and has a cross section having a diameter d ₂ that is the same as the diameter d ₁ of the fiber-reinforced plastic 4 laminated on the rim portion 1 .

First, to form the silicone rubber part 7 for preventing extrusion, as shown in FIG. Inject silicone rubber and cure at room temperature. Next, the core metal 11 is taken out from the recess 9 and the cured silicone rubber is demolded. An adhesive is applied to one side of the demolded recess 9, and the demolded silicone rubber is fitted and firmly adhered to form the upper and lower extrusion-preventing silicone rubber parts 7, as shown in FIG.

Fiber-reinforced plastic 4 laminated on rim portion 1
For pressure curing, the above-mentioned mold 6 is used, the upper and lower molds are opened, and an uncured laminate in which a fiber-reinforced plastic 4 is laminated on a ring-shaped lightweight foam member 3 with suppressed foaming is set. , close the mold. Next, the upper and lower molds 6 are pressed and heated by the heating press section 10.
On the other hand, closed-cell cells manufactured by press-fitting a foam material such as rigid urethane foam, polyethylene, polypropylene, polystyrene, vinyl chloride resin, urea resin, or phenol resin into a mold cooled at a temperature ranging from room temperature to 0°C By using a lightweight foam member with so-called foaming suppressed, the remaining portion that was suppressed from inside the fiber-reinforced plastic 4 during heating is re-foamed, and the molding pressure due to expansion and pressurization causes the foam to remain inside during wet molding. Remove the air bubbles and air bubbles between the prepreg layers from the mold 6.
Defoaming is done through the defoaming port 13 inside. At this time, the expansion pressure during heating, that is, the molding pressure, can be arbitrarily adjusted by controlling the degree of suppression of foaming before heating by the temperature and the degree of press-in, and the fibers of the fiber reinforced plastic 4 to be molded accordingly. Volume content (Vf) can be changed arbitrarily. In addition, when the fiber-reinforced plastic 4 is pressed into the recess 9 of the mold 6 by the expansion pressure of the lightweight foam member 3, silicone rubber is provided at the mating part of the mold, so that the fiber-reinforced plastic 4 does not protrude. It is possible to prevent a decrease in strength due to cutting of the reinforcing fibers when cutting the parts.

〔Effect of the invention〕

As described above, according to the present invention, in the case where the outer surface of a foamed member with suppressed foaming is coated with fiber-reinforced thermosetting plastic and cured by heating in a mold, In addition, silicone rubber was provided to prevent the fiber-reinforced plastic from extruding out, and the molding pressure for the covering was generated by foaming the foam member when the covering was heated and cured, so that the molds could be assembled easily. The fiber-reinforced plastic no longer protrudes from the fiber-reinforced plastic, and the foamed member whose foaming has been suppressed by heating re-foams, creating molding pressure that defoames the air bubbles in the fiber-reinforced plastic, thereby obtaining a strong plastic molded product. This has the effect of providing a method for manufacturing plastic molded products that can be used to produce plastic molded products.

[Brief explanation of drawings]

FIG. 1 is a plan view of a mold according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line B-B in FIG. 1, and FIG.
The figure is a partial sectional view of the mold showing the molded state of the silicone rubber part for preventing extrusion, and FIG. 4 is a partial sectional view of the mold showing the state of attachment of the silicone rubber part for preventing extrusion. FIG. 5 is a front view of the lightweight steering wheel, and FIG. 6 is a sectional view taken along line A--A in FIG. In the figure, 1 is the rim part, 2 is the spoke part, and 3
4 is a lightweight foam member, 4 is a fiber-reinforced plastic, 5 is a lightweight foam member
6 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 the recessed part, 10 is the hot press part, 11 is the core bar, 12 is the injection port, and 13 is the removal part. It is a bubble mouth. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A coating in which a fiber-reinforced thermosetting plastic is coated on the outer surface of a foamed member with suppressed foaming and cured by heating in a mold, in which the covering body is heated and cured in a mold, and A plastic molded product characterized in that silicone rubber for preventing extrusion of the fiber-reinforced plastic is disposed, and the molding pressure of the covering is generated by foaming the foamed member when the covering is heated and cured. Production method. 2. A plastic molded article according to claim 1, characterized in that a foamed member having closed cells prepared by press-fitting a foamed material into a low-temperature mold below room temperature is used as the foamed member with suppressed foaming. manufacturing method. 3. The plastic according to claim 1 or 2, characterized in that the fiber-reinforced thermosetting plastic is reinforced with one of glass fibers and carbon fibers and has an epoxy resin matrix. Method of manufacturing molded products.