JP2003094459A - Injection-molding die, and manufacturing method for molded article using the die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection-molding die which can reduce manhours for an injection-molding and reduce the generation of wastes as well. SOLUTION: This injection-molding die is constituted of a first die 1 equipped with a resin injecting path 11, and a second die 2 which forms a molding cavity 4 by cooperating with the first die 1. On the joined surfaces of both dies, a first seal member 7 which surrounds the molding cavity 4, and a second seal member 8 which is located on the inside of the first seal member 7, and surrounds the molding cavity 4 are provided. The first seal member 7 comes into contact with the joined surfaces of both dies earlier than the second seal member 8 at the time of a closing, and displays the sealing function. In a region pinched by the first seal member 7 and the second seal member 8, a passage 9 for air suction, which is provided on either one of both dies, is provided. First, the first seal member 7 is brought into contact with the joined surfaces of both dies, and air in the surrounded space is sucked out. In addition, the second seal member 8 is brought into contact with the joined surfaces of both dies, and a liquid-form resin 6 is injected.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an injection molding die,
The present invention relates to a method for producing a resin molded product using this mold.

[0002]

2. Description of the Related Art In injection molding, a reinforcing fiber base material and an insert are arranged in a molding cavity as needed, the molding cavity is decompressed, and a liquid resin is injected into the molding cavity to heat and cure it. Manufacture a prescribed molded product. The molding cavity is composed of a first mold having a resin injection path and a second mold cooperating with the first mold. In order to reduce the pressure of the molding cavity formed by mold clamping, Such a structure is adopted.

As shown in FIG. 3, an annular seal member 3 is located on the mating surface of the first mold 1 and the second mold 2, and the seal member 3 surrounds the molding cavity 4. There is. An air suction pipe 5 is attached to the seal member 3. The pipe 5 penetrates the seal member 3, and its tip is open in an area inside the seal member 3. In injection molding, the sealing member 3 is brought into contact with the mating surface of the first mold 1 and the second mold 2 by mold clamping, and the resin injection path 11
In the closed state, the air in the molding cavity 4 is sucked from the air suction pipe 5, and the molding cavity 4 is depressurized. Then, the resin injection path 11 is opened to inject the liquid resin 6 into the molding cavity 4, and the resin is cured by heating. To fully fill the molding cavity 4 with liquid resin,
It is necessary to inject the liquid resin in excess, and the excess resin penetrates into the air suction pipe 5 and hardens in the pipe.
Therefore, the air suction pipe 5 is removed from the seal member 3 and replaced with a new one each time it is molded.

[0004]

As described above, in the conventional injection molding, it is necessary to replace the air suction pipe each time it is molded, which not only requires a lot of man-hours but also the used air suction pipe as waste. I have to handle it.
The problem to be solved by the present invention is to provide an injection molding die capable of reducing the number of steps of injection molding and reducing the generation of waste. Moreover, it is providing the manufacturing method of the resin molded product which uses this metal mold | die.

[0005]

In order to solve the above-mentioned problems, an injection molding die according to the present invention comprises a first mold having a resin injection path, and a molding in cooperation with the first mold. Although it is composed of a second mold that forms a cavity, it is characterized by the following points. That is, a first sealing member that surrounds the molding cavity and a second sealing member that is located inside the first sealing member and surrounds the molding cavity are provided on the mating surfaces of the first mold and the second mold. Prepare The first seal member comes into contact with the mating surfaces of the first mold and the second mold earlier than the second seal member at the time of mold clamping to exert a sealing function, and the second seal member is the first seal member.
The sealing function is exhibited by contacting the mating surfaces of the first mold and the second mold later than the sealing member. Then, in the region sandwiched by the first seal member and the second seal member, the first seal member
An air suction passage provided in the mold or the second mold is open.

The production of a resin molded product using the above mold is carried out as follows. First, the mold is clamped until the first seal member comes into contact with the mating surfaces of the first mold and the second mold. The resin injection path is closed. Thereby, the space including the molding cavity surrounded by the first seal member is sealed. In this state, the air in the molding cavity is sucked from the air suction passage to reduce the pressure of the molding cavity. Further, the second seal member is brought into contact with the mating surfaces of the first mold and the second mold. By this operation, the space including the molding cavity surrounded by the second seal member becomes a space isolated inside the space surrounded by the first seal member. While maintaining this state, the resin injection path is opened and the liquid resin is injected into the molding cavity for molding.

The liquid resin injected into the molding cavity remains in the space surrounded by the second seal member and does not flow into the region sandwiched between the first seal member and the second seal member. Needless to say, the liquid resin does not reach the air suction passage, and the mold may be cleaned mainly in the inner region surrounded by the second seal member.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. As described above, the injection mold according to the present invention includes the first mold 1 having the resin injection passage 11 and the second mold 2 that cooperates with the first mold 1 to form the molding cavity 4. Composed of. A first seal member 7 and a second seal member 8 are arranged on the mating surfaces of the first mold 1 and the second mold 2. The first seal member 7 and the second seal member 8 are arranged so as to surround the molding cavity 4, respectively, and
The seal member 8 is located in a region inside the first seal member 7. An air suction passage 9 provided in the first mold 1 or the second mold 2 is opened in a region sandwiched by the first seal member 7 and the second seal member 8 (see FIG. The state where the air suction passage 9 is arranged in the mold 2 is shown).

Here, the first seal member 7 comes into contact with the mating surfaces of the first mold 1 and the second mold 2 earlier than the second seal member 8 during mold clamping. For example, the first seal member 7 and the second seal member 8 are rings made of a rubber-like elastic body such as silicone rubber, and are positioned in the recessed grooves provided on the mating surface of the second mold 2. By setting the cross-sectional diameter of the first seal member 7 to be larger than the cross-sectional diameter of the second seal member 8, the first seal member 7 projects from the second seal member 8.

Molding is carried out as follows using the above injection molding die. First, mold clamping is performed until the first seal member 7 comes into contact with the mating surfaces of the first mold 1 and the second mold 2 and elastically deforms and comes into close contact with the mating surfaces. At this time, since the resin injection path 11 is closed, the liquid resin 6 (crosslinked polyaminoamide, epoxy resin, etc.) does not flow in, and the space including the molding cavity 4 surrounded by the first seal member 7 is sealed. In this state in which the second seal member 8 is not yet in contact with the mating surfaces of the first mold 1 and the second mold 2, the air in the molding cavity 4 is sucked from the air suction passage 9 and the molding cavity 4 is closed. Depressurize (Fig. 1). Incidentally, a reinforcing fiber base material and an insert are arranged in advance in the molding cavity 4 as needed.

Further, mold clamping is advanced until the second seal member 8 comes into contact with the mating surfaces of the first mold 1 and the second mold 2 and is elastically deformed to come into close contact with the mating surfaces. By this operation, another sealed space including the molding cavity 4 is formed inside the first seal member 7. While maintaining this state, the resin injection path 11 is opened to inject the liquid resin 6 into the molding cavity 4 (FIG. 2). The liquid resin is cured by heating, and predetermined molding is performed.

Since the molding cavity 4 is under reduced pressure,
The liquid resin 6 is well injected. The surplus liquid resin after filling the molding cavity 4 is the second seal member 8
Since it is dammed up by, it does not flow into the area surrounded by the first seal member 7 outside the space surrounded by the second seal member 8. Liquid resin is air suction passage 9
Of course, it never reaches.

Therefore, it is not necessary to replace the air suction pipe 5 with a new one each time the molding is performed, which is performed by the conventional technique, and the number of manufacturing steps can be reduced. The mold may be cleaned mainly in the inner area surrounded by the second seal member 8.

In the embodiment of the invention described above, when the second seal member 8 is brought into contact with the mating surfaces of the first mold and the second mold, the first seal member 7 is largely deformed. Each time molding
Since this large deformation is repeated, the deterioration of the first seal member 7 is likely to be accelerated. Therefore, the first seal member 7 is supported by a backup member that deforms or retracts when a pressing force of a predetermined amount or more is applied, and the second seal member 8 is connected to the first mold and the second mold.
The deformation of the first seal member 7 that occurs when the first seal member 7 is brought into contact with the mating surface of the mold may be relaxed. When the second seal member 8 comes into contact with the mating surfaces of the first mold and the second mold, the stress on the first seal member 7 increases, and the stress causes the backup member to be deformed or retracted. Seal member 7
It alleviates the deformation of. Besides, the mold is clamped only once, and first, the first seal member 7 is brought into contact with the mating surface of the first mold and the second mold by mold clamping, and the air in the space surrounded by the first seal member 7 is removed. The suction may be performed, and thereafter, the second seal member 8 supported by the backup member may be advanced and brought into contact with the mating surface of the first mold and the second mold.

[0015]

As described above, the injection molding die according to the present invention, when sucking the air in the molding cavity,
Therefore, the number of man-hours required for incidental work can be reduced, and the generation of members to be handled as waste can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an embodiment of an injection molding die according to the present invention, which is a step before injecting a liquid resin into a molding cavity.

FIG. 2 is a cross-sectional explanatory view showing a step of injecting a liquid resin into a molding cavity, showing an embodiment of an injection molding die according to the present invention.

FIG. 3 is a cross-sectional explanatory view of a conventional injection molding die.

[Explanation of symbols]

1 is the first mold 2 is the second mold 3 is a seal member 4 is the molding cavity 5 is a pipe for air suction 6 is a liquid resin 7 is the first seal member 8 is a second seal member 9 is a passage for air suction 11 is a resin injection path

Claims (2)

[Claims] 1. A first mold having a resin injection path, and the first mold.
A second mold that cooperates with the mold to form a molding cavity; a mating surface between the first mold and the second mold includes a first sealing member surrounding the molding cavity; A second seal member that is located inside the seal member and surrounds the molding cavity is provided, and the first seal member is located on the mating surface of the first mold and the second mold earlier than the second seal member during mold clamping. The second seal member is brought into contact with the seal member to exhibit the seal function, and the second seal member exhibits the seal function later than the first seal member, and the first seal member and the second seal member sandwich the first seal member with the first seal member. An injection molding die, characterized in that an air suction passage provided in the die or the second die is opened. 2. Using the injection molding die according to claim 1, first, the mold is clamped until the first seal member comes into contact with the mating surface of the first mold and the second mold, and the resin injection path is closed. Air in the molding cavity from the air suction passage while
The molding cavity is depressurized, the second sealing member is further brought into contact with the mating surfaces of the first mold and the second mold, and then the resin injection path is opened to inject the liquid resin into the molding cavity. A method of manufacturing molded products.