JPH04339636A - Molding method - Google Patents

Abstract

PURPOSE:To improve flowability of a filling agent by engendering the same action as that to be obtained by lowering apparent viscosity of the filling agent, by oscillating a molding tool at the time of casting of the filling agent. CONSTITUTION:A molding tool 1 is supported under a floating state by a supporting frame 3. In other words, the supporting frame 3 supports both ends of the molding tool in the direction where a mixed material including a filling agent cast through a casting port 2 flows. As structure of a supporting part for the supporting frame 3 and molding tool 1, it is made into, for example, either supporting structure for which a shaft is used so that rocking of the molding tool 1 is performed or supporting structure which is constituted of a rod and fitting hole so that a movement can be performed in the right and left directions. Then the supporting frame 3 is constituted so that it can be oscillated laterally or vertically and the filling agent cast into a cavity IC can be rocked by an oscillation source.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method, and more particularly to an RTM molding method.

0002

[Prior Art] One of the molding methods in which a reinforcing material such as glass fiber is impregnated with a thermosetting resin and a molded product is obtained by a reaction between the two is called RTM (Resin Transfer
There is a molding method called "molding". In the above-mentioned RTM, a thermosetting resin such as polyester, silicone, unsaturated polyester, or epoxy is injected into a mold filled with reinforcing material such as glass fiber, and reaction hardening occurs through impregnation between the two. It is being done.

0003

[Problem to be solved by the invention] By the way, the above-mentioned R
In TM, the conditions for the resin used as a filler include that it has a low viscosity, that it maintains a low viscosity during the injection process, that the reinforcing fibers are well wetted, and that the curing reaction is not too rapid. The above-mentioned filler may contain a high viscosity or foamable calcium carbide, which may result in poor fluidity during injection into a mold. The above-described deterioration in fluidity may lead to poor impregnation of the resin into the reinforcing fibers, poor defoaming in which the removal of bubbles from the resin deteriorates, and furthermore, a reduction in the molding cycle. be.

[0004] Therefore, an object of the present invention is to provide a molding method that can prevent the occurrence of poor impregnation of the reinforcing material and defoaming, as well as a reduction in the molding cycle, in the conventional RTM described above. .

[0005]

[Means for Solving the Problems] In order to achieve this object, the present invention involves loading reinforcing fibers into the cavity of a mold consisting of a male die and a female die, and heating the reinforcing fibers as a filler in the cavity. In the RTM molding method, in which curable resin is injected to impregnate reinforcing fibers with filler and molded by reaction curing,
The present invention is characterized in that at least a portion of the cavity in the mold where the fluidity of the filler tends to deteriorate is vibrated when the filler is injected.

The present invention is also characterized in that the entire mold is vibrated.

Furthermore, the present invention is characterized in that vibration is applied to the bent portion of the cavity.

[0008]

According to the present invention, the apparent viscosity of the injected filler can be lowered by vibration, thereby improving the fluidity.

[0009]

[Embodiment] Details of an embodiment of the present invention will be explained below with reference to FIGS. 1 and 2.

FIG. 1 is a model diagram of a mold for carrying out a molding method according to an embodiment of the present invention. In the figure, a mold 1 is composed of a male mold 1A and a female mold 1B, and the mold 1 is composed of a male mold 1A and a female mold 1B. A cavity 1C that follows the shape of the molded product is formed at the facing position. The above-mentioned cavity 1C is connected to an injection port 2 through which a mixture of a thermosetting resin as a filler and a polymerization initiator and accelerator as a catalyst is injected.

On the other hand, the molded product obtained by the mold 1 shown in FIG. 1 has a plurality of bent portions due to the shape of the cavity 1C. The mold 1 described above is
It is supported in a floating state by a support frame 3. That is, the support frame 3 described above is located at both ends of the mold 1 in the direction in which the filler and other mixed materials injected from the injection port 2 flow, or in the case of the illustrated embodiment, at both left and right sides with respect to the plane of the paper. I support it. The structure of the support part between the support frame 3 and the mold 1 may be, for example, a support structure using a shaft so that the mold 1 can be swung, or a support structure that is fitted with a rod so that it can move in the left and right direction. It is conceivable to use a support structure composed of a matching hole.

[0012] The support frame 3 described above can be vibrated horizontally or vertically by a vibration source (not shown), and can shake the filling material injected into the cavity 1C. . As the above-mentioned vibration source, for example, the support frame 3 is intermittently caused by rotation.
A mechanism for striking or a similar mechanism for transmitting vibrations is used, and the vibration frequency is selected to the extent that it does not impair defoaming properties and does not adversely affect reaction hardening. is, for example, in the range of 5 to 100 Hz.

In this embodiment, for example, glass fiber reinforcement is loaded into the cavity 1C as reinforcing fibers, and after the mold is clamped, a filler containing a thermosetting resin, a curing initiator, and an accelerator is poured into the injection port 2. Inject from. In conjunction with the injection of the filler, the mold 1 is vibrated in the direction of the arrow shown in the figure to reduce the apparent viscosity of the filler in the cavity 1C and set a state in which it can easily flow.

On the other hand, in the mold 1 described above, the fluidity of the filler is improved by vibrating the entire mold using a vibration source, but in the present invention, instead of such a method, the fluidity of the filler is improved by applying local vibrations. It is also possible to improve flowability.

FIG. 2 is a model diagram showing the mold 10 in the above-described case, and it is prefaced that in this figure, the same components as those shown in FIG. 1 are designated by the same reference numerals.

That is, the mold 10 is composed of a male mold 10A and a female mold 10B as in the case of FIG. A recess 11 is provided at a position facing the part whose shape is set, the thickness of which is reduced compared to the thickness of other parts. For example, an ultrasonic generator (not shown) is disposed in the recess 11 to induce vibration in the recess 11.

In this embodiment, the above-mentioned concave portion 11 is hardened by shaking the injected filler, especially the filler that tends to accumulate in the bent portion, by inducing vibrations from an ultrasonic generator. The aim is to improve liquidity before In addition, the frequency generated by the above-mentioned ultrasonic generator can be set without impairing the above-mentioned defoaming property, and
Not only is the value set to a value that satisfies that the reaction hardening property is not deteriorated, but also the cavity 10 is set depending on the direction of vibration generation.
The amplitude is set so that the dimension of C does not change.

Furthermore, the portion corresponding to the above-mentioned recess 11 is not limited to being formed by a part of the female mold 10B, but may be formed by, for example,
It may also have a structure in which it is separated from a part of the female mold 10B.

[0019]

As described above, according to the present invention, in the RTM molding method in which a reinforcing material is impregnated with a filler containing a thermosetting resin and cured by reaction, the mold is not vibrated when the filler is injected. Therefore, the fluidity of the filler can be improved by producing the same effect as reducing the apparent viscosity of the filler within the cavity.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a mold for carrying out a molding method according to an embodiment of the present invention.

FIG. 2 is a model diagram corresponding to FIG. 1 showing a modification of the mold shown in FIG. 1;

[Explanation of symbols]

1, 10 Molding mold 1A, 10A male type 1B, 10B female type 1C, 10C Cavity 2 Inlet 3 Support frame 11 Recessed part

Claims (3)

[Claims] Claim 1: Reinforcing fibers are loaded into the cavity of a mold consisting of a male mold and a female mold, and a thermosetting resin is injected as a filler into the cavity to impregnate the reinforcing fibers with the filler. In the RTM molding method, which involves molding by reaction hardening,
A molding method characterized in that at least a portion of the cavity in the mold where the fluidity of the filler tends to deteriorate is vibrated when the filler is injected. 2. The molding method according to claim 1, wherein the entire mold is vibrated. 3. The molding method according to claim 1, wherein vibration is applied to the bent portion of the cavity.