JPH039815A - Resin molding die - Google Patents

Abstract

PURPOSE:To prevent generation of defective molding such as insufficient filling, by a method wherein at least a surface layer part of a mold containing a molding surface out of either one side mold of a male mold or a female mold is constituted displaceably in a mold clamping direction to a mold main body. CONSTITUTION:Upon mold clamping of a bottom and top force 1, 2 by setting up a glass fiber G of a reinforcing material on the bottom force 1, negative pressure is generated within a space 6 of the top force 2 by moving backward a plunger 10 of a pressurizing cylinder 8. An elastic deformation of an auxiliary mold 5 is performed in the direction spreading a space R of a product part from its base part. Then a resin material M is filled into the space R of the product part by moving forward a plunger 12 of an injection machine 3. In this instance, since the space R of the product part is spread out a little larger than regular form capacity of the product, the same is filled with at least the necessary quantity of the resin material M. Then positive pressure is applied to the auxiliary mold 5 by moving forward the plunger 10 of the pressurizing cylinder 8 again and restoration and deformation are preformed so that capacity of the space R of the product part becomes the regular product capacity. Consequently, surplus resin material M is discharged through the space R of the product part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resin mold, and more specifically to a mold suitable for the resin injection mold (resin transfer mold) method, which is one of the molding methods for thermosetting resin. Regarding resin molds.

Conventional technology The resin injection method, which is one of the methods for molding thermosetting resin, uses a lower mold 5 which is a female mold as shown in Fig. 6, for example.
A sheet-like reinforcing material 52 such as glass fiber is placed on top of the lower mold 51 and an upper mold 53 which is a male mold, and then the product defined by both molds 51 and 53 is formed. Although it is characterized in that the resin material M is solely filled into the part space R by injection 854, the structure of the mold itself is not particularly different from that of a general mold.

Problems to be Solved by the Invention In the resin injection method as described above, when trying to increase the content of the reinforcing material 52 in order to reduce the weight and increase the rigidity of the molded product, the lower mold 51 and the upper mold 53 Since the clearance between the molded parts (thickness of the molded product) is constant, the higher the content of the reinforcing material 52, the higher the density of the reinforcing material 52 in the mold. It is difficult to fill every corner of the part space R, resulting in molding defects such as insufficient filling.

The present invention was made in view of the above problems.
The present invention provides a resin mold structure in which a molded product with a high content of reinforcing material can be easily obtained by configuring a part of the mold to be displaceable.

Means for Solving the Problems The present invention provides a resin molding mold in which a product space is formed by a pair of male and female molds that are clamped together as described above. The surface layer portion of the mold including at least the molding surface is configured to be movable in the mold clamping direction with respect to the mold body, and a pressure transmission fluid is retained between the internal space defined by the mold body and the surface layer portion; Furthermore, the present invention is characterized in that a pressurizing means is provided for displacing the surface layer portion of the mold via a pressure transmission fluid.

According to this structure, when filling with the resin material, the surface layer of one mold is positioned at a position where a product space slightly larger than the regular product volume can be secured, and then the resin material is filled.

After filling, the surface layer of one mold is displaced to the regular product shape position to secure a product space equivalent to the regular product volume, and the resin material is substantially pressurized and excess resin material is discharged. Molding is performed by this.

Therefore, when molding a product containing a reinforcing material as described above, even if the content of the reinforcing material is increased, at least when filling with the resin material, a space in the product part that is larger than the regular product volume is secured. This prevents the density of the reinforcing material from becoming extremely high (and allows smooth filling of the resin material).

Embodiment FIG. 1 is a diagram showing a more specific embodiment of the present invention.
2 is a lower mold as a female mold equipped with a molding surface 1a; 2 is an upper mold as a male mold also equipped with a molding surface 5a; 3 is an injection machine for filling resin material M; The molding surface 1a is formed by clamping the mold.

A product space (cavity) R is formed between 5a.

The upper mold 2 is an auxiliary mold for forming the surface layer of the upper mold 2, that is, an auxiliary mold 5 having a predetermined thickness and a molding surface 5a, which is integrally fixed to a hollow mold main body 4. A space 6 formed by the main body 4 and the auxiliary die 5 is filled with, for example, oil 7 as a pressure transmitting fluid. The space 6 communicates with a pressure chamber 11 defined by a cylinder tube 9 of a pressurizing cylinder 8, which is pressurizing means, and a plunger lO. .

When molding a thermosetting fiber-reinforced resin molded product using such a resin mold, first, as shown in Fig. 2, glass fiber G, which is a reinforcing material, is set on the lower mold 1. 1 and the upper mold 2, the plunger IO of the pressure cylinder 8, which had been in the neutral position (see Fig. 1),
is retracted to generate a negative pressure in the space 6 of the upper mold 2, thereby elastically deforming the auxiliary mold 5 from its base in a direction that expands the product space R, as shown by the solid line in FIG.

Then, in this state, as shown in FIG. 3, the plunger 12 of the injection machine 3 is moved forward to fill the product part space R with the resin material M. At this time, as mentioned above, the product space R is slightly expanded by the deformation of the auxiliary mold 5 compared to the normal product shape volume, so the resin material M reaches every corner of the product space R (as well as the product Part space R is filled with resin material M in an amount greater than the required amount.

Once the product space R is filled with the resin material, the plunger 10 of the pressure cylinder 8 is moved forward again to apply positive pressure to the auxiliary mold 5, as shown in FIG.
The product is restored and displaced to the regular product shape position so that the volume becomes the regular product volume. As a result, as is clear from comparing FIG. 3 and FIG. At the same time as the glass fibers G are returned to the side and discharged from the product space R, the glass fibers G themselves are also compressed to increase their density.

Then, a fiber-reinforced resin molded product as a product is molded by keeping the state shown in FIG. 4 under a holding pressure state for a predetermined period of time.

FIG. 5 shows another embodiment of the present invention. In the previous embodiment, the auxiliary mold 5 forming the surface layer of the upper mold 2 was configured to be elastically deformed, whereas in this embodiment, the auxiliary mold 5 forming the surface layer of the upper mold 2 The mold 15 is divided from the mold body 4 and configured to be slidable relative to the mold body 4 in the mold clamping direction.

More specifically, as shown in FIG. 5, an auxiliary mold 15 as a surface layer having a molding surface 15a is configured to be movable up and down relative to the mold body 4, and a space formed by this auxiliary mold 15 and the mold body 4 6 is filled with, for example, oil 7 as a pressure transmitting fluid as in the previous embodiment. Therefore, in this embodiment as well, the same effects as in the first embodiment can be obtained by moving the auxiliary mold 15 up and down.

Effects of the Invention As described above, according to the present invention, the surface layer of either the male mold or the female mold, including at least the molding surface, is configured to be movable in the mold clamping direction with respect to the mold body. This makes it possible to change the volume of the product space before and after the displacement. As a result, in the resin injection method in which only the resin material is later filled into the product space where the reinforcing material has been placed in advance, the density of the reinforcing material is kept low at the time of filling the resin material, and after filling the resin material, For the first time, it will be possible to increase the density of the reinforcing material to a predetermined density, making it possible to prevent molding defects such as insufficient filling and easily mold products with a high content of reinforcing material. .

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, FIG.
3 and 4 are explanatory views of the operation of the resin molding die shown in FIG. 1, FIG. 5 is a configuration explanatory view showing another embodiment of the present invention, and FIG.
The figure is a configuration explanatory diagram showing an example of a conventional resin mold. ■... Lower mold as female mold, 1a... Molding surface, 2...
・Upper mold as male mold, 4... mold body, 5, 15...
Auxiliary type, 5a... Molding surface, 6... Space, 7... Oil as pressure transmission fluid, 8... Pressure cylinder as pressurizing means, G... Glass fiber as reinforcing material , M.
...Resin material, R...Product department space. Figure 3 Figure 4

Claims (1)

[Claims] (1) In a resin molding mold in which a product space is formed by a pair of male and female molds that are clamped, the surface layer of either the male mold or the female mold, which includes at least the molding surface, is The mold is configured to be displaceable in the mold clamping direction with respect to the mold body, retains a pressure transmission fluid in an internal space defined by the mold body and the surface layer, and further displaces the surface layer of the mold via the pressure transmission fluid. A resin molding mold characterized by being equipped with a pressurizing means.