JP3317483B2 - Thermosetting resin molding die and molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin molding die and a molding method using the die.

[0002]

2. Description of the Related Art Phenolic resin molding materials are used in a wide range of applications such as automobile parts, electronic / electric parts, and mechanical parts because of their excellent heat resistance, electric performance and mechanical performance. However, since the phenol resin molding material generates a gas during molding, it is necessary to provide a gas vent in the mold in order to release the gas from the inside of the cavity. In addition, if the gas cannot be sufficiently released by gas venting alone, the product part (hereinafter referred to as “stemold”) is premised on removing the molded product by post-processing and removing it from the mold where short shots occur due to this gas. Call).

On the other hand, burrs are generated when molten molding material leaks from a narrow gap such as a parting surface of a mold or a gas vent during molding of the molding material, and is generated in the mold in comparison with a thermoplastic molding material. The thermosetting resin material having a low melt viscosity has a problem that burrs are easily generated. Generally, burrs refer to the material that has flowed into the gap between the parting surface and the mold pieces, but in the present invention, the material that has flowed into the thin gas vent is also referred to as burrs. If the burrs remain in the gas vent portion of the mold, the gas vents may cause short shots. It is strongly desired to reliably remove burrs remaining on the gas vent from the mold for each molding shot in order to stably perform phenol resin molding.

[0004]

SUMMARY OF THE INVENTION According to the present invention, burrs adhering to a gas vent provided at a cylindrical tip portion of a mold for molding a cylindrical product having a cylindrical shape having a dead end shape are easily and reliably removed. Therefore, the purpose of this study was to provide a second parting surface on the mold to ensure that the burrs remaining on the mold could be reliably removed. It is an object of the present invention to provide a mold capable of continuous molding and a molding method using the mold.

[0005]

According to the present invention, there is provided (1) a molded article having a cylindrical shape whose tip is a dead end.
Take out the molded product in a mold for molding
Besides the parting surface for
That the second parting surface is provided
Thermosetting resin molding die and symptoms, (2) after curing of said molded article, said second parting surface
Open the mold where burrs are formed at the tip of the molded product
Exposing the part, air blowing, brush, etc., mold
(1) characterized in that the burrs attached to the surface are removed.
Molding method using a thermosetting resin molding die described in
is there.

Hereinafter, a detailed description will be given with reference to FIGS. 1 and 2. 1A and 1B are views showing a conventional mold structure, in which FIG. 1A is a cross-sectional view, and FIG. 1B is a cross-sectional view along AA of FIG. 1 represents the shape of the molded product. At the tip of the cylindrical portion 2 of the molded product, the die is formed into a dead end, so that six to eight gas vents 3 are conventionally provided in a D-cut shape (FIG. 1 (b)). The gas vent did not come off, or the gas vent was clogged by the burrs that flowed into it, and short shots and rough skin due to gas occurred in the molded product.
Therefore, assuming that the molded product is post-processed to remove burrs, a material reservoir (ste mold) 4 connected to the tip is provided in the mold at the tip end, and the same D above as above is provided.
A cut-shaped gas vent 3 is installed, and a molding material is poured into the stem mold 4 to cause short shots and rough skin which are defective defects due to the gas in the stem mold portion,
The original product was designed so that no defective defect appeared.

However, even in this case, if the gas vent 3 at the tip of the stem mold 4 is clogged by the burrs 5 flowing during molding , a defect due to gas may appear in the product part. Further, it is sufficient that the burr 5 flowing into the gas vent adheres to the stem mold 4 for each molding shot and separates from the mold. However, if the burr 5 is torn off and remains in the mold, the molding is performed with the gas vent clogged. The above defects occur. In order to recover this, there has been no effective means for removing this burr other than disassembling and cleaning the mold.

FIGS. 2 and 3 show a specific example of the present invention. FIG. 2A is a sectional view, and FIG. 2B is a sectional view taken along line BB of FIG. 2A. The removal of the burr 13 which had no other effective means than the conventional technique other than disassembling and cleaning the mold can be easily and reliably removed from the gas vent by providing the second parting surface 15 in the mold. it can. The movable core pin 6 is fixed to the movable mold plate B11, so that when the movable mold plate A10 is moved, the gas vent 12 engraved on the movable core pin 6 becomes visible from the outside of the mold. The opening 15 can be opened. That is, since the burr 13 remaining on the gas vent is attached to the movable core pin 6, the burr 13 is exposed to the outside and can be processed from outside the mold. This makes it possible to easily remove the burrs 13 remaining in the gas vent by blowing high-pressure air or rubbing with a brush or the like on the burrs from outside the mold.

In order to open the second parting surface, the movable mold plate A is actuated by connecting the fixed mold plate 7 and the movable mold plate A10 with a pull ring or the like to open the mold. , It may be opened for each shot. By doing so, the burrs 13 remaining in the gas vent can be easily removed for each shot, and therefore, continuous molding without defects due to gas becomes possible. Further, the method of opening the second parting 15 may be any method other than the above-mentioned means as long as it has a structure that can be opened and closed for each molding shot.

[0010]

According to the present invention, in a mold for molding a molded article having a cylindrical shape whose tip is a dead end, a gas vent is provided at the tip in order to prevent a defect at the tip of the molded article cylinder due to gas. At the time of installation, a second parting surface should be installed on the mold so that the burr portion that has flowed into the gas vent can be exposed outside the mold, and the second parting should be opened and closed for each molding shot. Accordingly, burrs that flow into the gas vent and clog the gas vent can be easily and reliably removed by blowing high-pressure air from outside the mold or rubbing off with a brush or the like for each molding shot. Therefore, it is possible to achieve a molding method that does not cause a defect at the tip of the molded article cylindrical portion.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a conventional mold for forming a molded product having a cylindrical shape with a tip portion having a shape of a dead end,
(B) is an AA cross-sectional view of (a).

2A is a cross-sectional view of the mold of the present invention immediately after molding, and FIG. 2B is a cross-sectional view taken along line BB of FIG.

FIG. 3 is a cross-sectional view showing a state in which the first and second parting surfaces are opened after molding with the mold of the present invention and a molded product is taken out.

[Explanation of symbols]

 Reference Signs List 1 Molded product 2 Cylindrical part 3 Gas vent 4 Stem mold 5 Burr flowing into gas vent during molding 6 Movable core pin 7 Fixed mold plate 8 Movable mold plate 9 Parting surface 10 Movable mold plate A 11 Movable mold plate B 12 Gas vent 13 Burr remaining on gas vent 14 First parting surface 15 Second parting surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/26-45/37 B29C 45 / 63,33 / 10,33 / 42

Claims (2)

(57) [Claims] 1. A mold for molding a molded article tip has a cylindrical shape that is dead end shape, in addition to the parting surface for taking out the molded article, the molded article tip
A mold for molding a thermosetting resin, wherein a second parting surface is provided at a portion where a burr occurs in a portion . 2. The method according to claim 1 , further comprising the step of:
Opening the bearing surface, burr at the tip of the molded product
Exposed mold part is exposed,
And removes burrs attached to the mold.
A molding method using the thermosetting resin molding die according to claim 1.
Law.