JPH09216239A - Resin molding die and manufacture of resin molded item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily take out a resin hardened in a resin bank after molding by forming a pair of resin banks from a resin bank of one split die and a resin bank of the other split die. SOLUTION: A cavity 3 communicates with resin banks 5, 5' of an upper split die 1 through gates 8, 8'. The resin bank 5 of the die 1 communicates with a resin bank 4 of a lower split die 2 through a parting surface 10, while the bank 5' of the die 1 communicates with a resin bank 4' of the die 2. Since there are banks 5, 5' between the die 1 and the die 2 through a parting surface 10, when the dies are opened, one of the resin banks 5 can be surely caught. By pulling out a hardened resin in the other bank 5' by catching a hardened resin produced in one of the banks 5, the hardened resin can be easily pulled out.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to injection of liquid or molten resin into a cavity having a product shape formed in a mold, such as so-called resin injection or injection molding for producing various resin molded products. The present invention relates to a resin mold for manufacturing a resin molded product by the method and a method for manufacturing a resin molded product.

[0002]

2. Description of the Related Art A method for producing a resin molded article by injecting a liquid or molten resin into a cavity having a product shape formed in a mold, such as so-called resin injection or injection molding, is a thermosetting method. It is widely used regardless of the resin and the thermoplastic resin. One of the important things in the production of such a resin molded product is to take out the molded product from the mold after molding, that is, there is a problem of demolding, but in a mold having a resin reservoir communicating with the cavity, It is necessary to easily take out not only the molded product, but also the cured product that remains in this resin pool. Conventionally, a mold equipped with an ejector pin or a hook pin was used to take out the cured resin from the resin pool, but the mold structure becomes complicated and the mold becomes expensive, and resin entrapment occurs. Due to this, it was necessary to replace the parts.

The above resin molded products naturally include fiber reinforced plastics reinforced with glass fibers, carbon fibers or the like as a reinforcing material. However, the method of molding these resin molded products involves reducing the cavity pressure. There is a method of molding by injecting a low-viscosity liquid resin. For example, there is an RTM molding method using carbon fibers or glass fibers as reinforcing fibers.

In this method, a mold having a cavity surrounded by a sealing material may be used as a mechanism for imparting a sealing property to the mold. As for the sealing method, for example, the sealing performance can be ensured according to a machine manual in which the shape and size of the groove for accommodating the sealing material and the size of the sealing material matching the size of the groove are described. That is, as a sealing material, an elastic rubber band is housed in a groove provided in one split mold, and when the mold is closed, it is sealed by the elasticity of the rubber band.

However, according to such a sealing method, the sealing material may easily come off from the groove when the mold is opened after molding or when the molded product is taken out. In this case, there is a problem that not only the work of housing the sealing material in the groove is required when moving to the next molding cycle, but also the sealing material is damaged during repeated use and the sealing property is deteriorated.

As described above, when the liquid resin is injected into the mold for molding, it is troublesome to remove the hardened material from the resin pool and to install the sealing material when the molded product is taken out or in the preparatory work for the next molding. Workability is reduced.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, and not only is it extremely easy to remove the mold after molding, but it is also easy to repeat molding and is excellent in sealing performance. Another object of the present invention is to provide a resin mold having a sealing mechanism and a method for manufacturing a resin molded product.

[0008]

The structure of the present invention for achieving the above object is as follows. That is, (1) a cavity having a desired shape of a molded product, one split mold provided with a resin reservoir communicating with the cavity, and the other split mold provided so as to be separable from and joined to the one split mold. The other split mold is provided with a resin pool at a position facing the resin pool of the one split mold via a parting surface, and the one split mold and the resin pool of the other split mold form a pair. A resin molding die, characterized in that the resin reservoir of (1) is formed. (2) The at least one split mold is provided with one split mold having a cavity having a desired molded product shape and another split mold provided so as to be joined and separated from the one split mold. A resin molding die having a groove having a narrow frontage for accommodating a sealing material.

(3) The resin molding die according to the above (1), characterized in that the at least one split mold is provided with a groove having a narrow frontage for accommodating a sealing material.

(4) The resin molding die according to the above (2) or (3), wherein the width of the frontage of the groove for accommodating the sealing material is 60 to 100% of the diameter of the sealing material.

(5) The cross-sectional area of the groove for accommodating the sealing material is
90-110% of the cross-sectional area of the sealing material, The resin molding die according to any one of (2) to (4) above.

(6) Using one of the resin molding dies described in (1), (3), (4) or (5) above, inject resin into the cavity, mold the resin, and then separate the respective mold halves. Next, a method for producing a resin molded product, characterized in that a cured resin that can be made into a resin pool is grabbed and a cured resin in another resin pool is pulled out.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a resin molding die according to one embodiment of the present invention.

In FIG. 1, split molds are an upper split mold 1 and a lower split mold 2.
Consists of In this split mold, when the upper split mold 1 is closed with respect to the lower split mold 2, a cavity 3 having a desired molded product shape is formed. The cavity 3 communicates with the resin reservoirs 5, 5'of the upper split mold 1 through the gates 8, 8 '.
Further, the resin pool 5 of the upper split mold 1 has a parting surface 1
0 to communicate with the resin pool 4 of the lower split mold 2, and similarly, the resin pool 5'of the upper split mold 1 becomes the resin pool 4'of the lower split mold 2.
Is in communication with Upper split mold 1 through the parting surface 10
Since the lower split mold 2 has a resin puddle, it is a requirement of the present invention that one of the resin puddle surely serves as a grip allowance when the mold is opened. That is, in the present invention, the cured resin can be easily extracted by pulling out the cured resin in the other resin reservoir while using the cured resin formed in the one resin reservoir as a grip.

In FIG. 1, reference numerals 9 and 9'indicate resin inlets or outlets. However, in the present invention,
It is not essential to provide this outlet 9 '.

When the resin reservoirs 5 and 5'are provided at necessary portions such as for controlling the flow of the resin, the resin reservoirs 4 and 4'to facilitate removal of the cured product of the resin reservoirs.
The provision of is a requirement of the present invention.

The resin pools 4, 4'5, 5'are wider at the parting surface 10 and narrower toward the back as shown in FIG. 1 in order to facilitate the escape of the cured resin. Therefore, it is preferable to provide a draft of about 0 to 20 °. Also, the resin pools indicated by 4, 4 ', when grasping the cured resin and pulling it out,
The capacity may not be torn off, but the capacity is preferably as small as possible. Further, it is preferable to apply or spray a release agent to the inside of the resin reservoir for easy removal.

The present invention further provides a resin molding die having a sealing material arranged in a split mold and a groove for accommodating the sealing material having a narrow cross section.

FIG. 2 is a plan view showing a sealing mechanism of a resin molding die according to an embodiment of the present invention.

When the upper split mold 1 is closed with respect to the lower split mold 2,
A cavity 3 having a desired molded product shape is formed. As shown in FIG. 2, this cavity 3 is isolated from the outside of the mold by a groove 6 and a sealing material 7. The sealing material 7 is housed in the groove 6 provided in the lower split mold 2, and in the mold closed state, the elastic recovery force of the sealing material 7 is utilized to make the sealing material 7
The sealing property is secured by bringing the parting surface 10 and the parting surface 10 into close contact with each other.

The sealing material 7 is made of, for example, plastic material having elasticity, and it is preferable that the sealing material 7 has a rubber cross-section having a round cross section. The material may be silicone rubber, butyl rubber, or any other material that can be used as a sealing material.

However, in the present invention, as shown in FIG. 2, the sealing material 7 may be arranged not only on the outer periphery of the cavity 3 but also on any portion for the purpose of sealing in accordance with the shape of the cavity 3. The split mold for arranging the grooves may be either an upper split mold or a lower split mold, or both.

3A, 3B and 3C are sectional views of the seal groove according to the embodiment of the present invention.

FIGS. 4 and 5 are cross-sectional views in which the seal material is housed in the seal groove according to the embodiment of the present invention.

The shape of the groove for accommodating the sealing material is shown in FIG.
As shown in (A), the parting surface 10 in contact with the split mold
It is characterized by a narrow front opening that prevents the stored seal material from coming off. Preferably, the width of the frontage of the groove 6 for accommodating the sealing material is 60 to 1 of the diameter of the sealing material 7.
00%.

Further, the shape of the groove 6 may be, for example, as shown in FIGS. 3 (B) and 3 (C) in order to make it easier to store the sealing material 7 in the groove 6, but the shape is not limited to this. .

Further, it is preferable that the groove has an appropriate size according to the size of the sealing material used. That is, in the state where the sealing material is housed in the groove, the sealing material protrudes from the groove as shown in FIG. 4, and the size is such that the sealing material fits almost completely in the groove when the mold is closed as shown in FIG. Preferably, the cross-sectional area of the groove is 90 to 110% of the cross-sectional area of the sealing material.

This mold can be preferably used in a molding method in which resin is injected under reduced pressure (for example, RTM method), but the present invention is not limited to this.

FIG. 6 shows a conventional sealing groove for comparison with the present invention.

[0030]

EFFECTS OF THE INVENTION The present invention makes it possible to easily take out the hardened resin in a resin pool after molding with a mold provided with a resin pool, and to easily clean up after the completion of molding and prepare for the next molding. And the workability is greatly improved. In addition, the present invention has a specific cross-sectional shape of the groove for accommodating the sealing material in the molding for reducing the cavity pressure or injecting the low-viscosity resin, so that after the completion of molding or for the next molding. Preparation becomes easier and workability is improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a sealing mechanism of a mold of an apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view of a seal groove according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a seal member accommodating a seal groove according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view of a seal material housed in a seal groove according to an embodiment of the present invention.

FIG. 6 is a sectional view of a seal groove according to a conventional embodiment.

[Explanation of symbols]

 1: Upper split type 2: Lower split type 3: Cavity 4,4 ': Resin reservoir 5,5': Resin reservoir 6: Seal material storage groove 7: Seal material 8,8 ': Slit gate 9,9': Resin Inlet or outlet 10: Parting surface

Claims (6)

[Claims] 1. A cavity having a desired shape of a molded article,
One split mold provided with a resin reservoir communicating with the cavity, and the other split mold provided so as to be joined and separated from the one split mold, and the other split mold is provided with the one split mold. A resin molding is provided at a position opposed to the resin collecting via the parting surface, and a pair of resin moldings are formed by the resin moldings of the one split mold and the other split mold. 2. A split mold provided with a cavity having a desired shape of a molded product, and a split mold provided so as to be joined and separated from the split mold, the split mold being at least one split mold. A resin molding die characterized in that the die is provided with a groove having a narrow frontage for accommodating a sealing material. 3. The resin molding die according to claim 1, wherein the at least one split mold is provided with a groove having a narrow frontage for accommodating a sealing material. 4. The resin molding die according to claim 2 or 3, wherein the width of the frontage of the groove for accommodating the sealing material is 60 to 100% of the diameter of the sealing material. 5. The resin molding die according to claim 2, wherein the groove for accommodating the sealing material has a cross-sectional area of 90 to 110% of the cross-sectional area of the sealing material. 6. A resin mold according to any one of claims 1, 3, 4 and 5 is used to inject a resin into a cavity,
After the molding, the split molds are separated from each other, and then the cured resin in the other resin pool is pulled out by using the cured resin that can be stored in the resin pool as a margin.