JPS61134211A - Mold - Google Patents

Abstract

PURPOSE:To enable mechanical strength of a molded article to improve, by making a core pin slide upward in turn through pressure of a molding molten material at the time of molding. CONSTITUTION:When a molding molten material 60 is cast into a casting port 41 through a cylinder, the molding molten material 60 arrives at the bottom of a cavity by flowing through the cavity to be formed first with a through hole 52 and a core pin 45. Then the molding molten material 60 has its escape cut off by casting further the molding molten material 60 into the casting port 41 through the cylinder, the tip of the core pin 45 is pressed through pressure of the molding molten material 60 and the core pin 45 pushed up toward the upper part. As the core pin is provided on a main body of a stationary mold slidably like this, mechanical strength of a molded article can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a molding die used, for example, in molding a ferrule of an optical fiber plastic connector (hereinafter referred to as an optical connector).

[Technical background of the invention and its problems]

As shown in FIG. 3 as an example of a conventional optical connector, there is a seven-erule 5 having a hole 2 into which the optical fiber core 1 is inserted, a microhole 4 of, for example, 125 μm into which the bare optical fiber 3 is inserted; 7 The sleeve 6 provided on the outer periphery of the errule 5 and the! It is comprised of a mold 10 and a movable mold 20 for joining J-16 and the seven errules 5 described above.

The fixed mold body 11010 is fixed to a fixed mold body 14 having a molding resin injection port 11, an f-id hole 12, and a core pin insertion hole 13, and a core bin insertion hole JJK'' of this fixed mold body 14, and a micro pin insertion hole. Core bin 1 with holes 16
It consists of 5. The movable mold 20 has a hole 21 and a guide pin 24 for setting the outer shape of the 7 errule 5.
A movable metal body 22 having a movable mold body 22 and a cavity insertion piece (micro pin holder) 23 provided at the bottom of the hole 21 of the movable mold body 22. It consists of a micro pin 25 that can be inserted into the insertion hole 16.

In order to perform molding using a molding tool having such a configuration, the fixed mold 10 and the movable mold 20 are combined as shown in FIG. The resin may be injected into the molding resin injection port 11. Ferrules made in this way have low mechanical strength and may break in some cases. In particular, the base of the ferrule's collar is easily broken.

7. In order to increase the mechanical strength of the ferrule, the protruding length of the micro ferrule 25 of the above-mentioned conventional molding die is lengthened, and its tip is extended close to the flange of the ferrule.
It is conceivable to shorten the protruding length of the pins 5, but in this case, the micro pins 25 may be deformed by the pressure when the molten resin 30 is injected, so this is not recommended.

[Purpose of the invention]

The present invention was made in view of these circumstances.
An object of the present invention is to provide a molding die that increases the mechanical strength of a molded product.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to the drawings. Here, a mold used for molding a ferrule of an optical connector will be described as an example, but the mold is not limited to this and may be used for molding other products. FIG. 1 is a cutaway view showing one embodiment of the molding die of the present invention, which is composed of a fixed die 40 and a movable die mso. A fixed mold body 40 includes a fixed mold body 44 having an injection port 41 for molten material for molding, a foid hole 42 and a core pin insertion hole 43, and a core bin 4.
It consists of 5.

This core bin 45 is rod-shaped, and has a 72-inch hole 45 at one end.
m is formed. The core bin 45 having such a structure is slidably (vertically movable) inserted into the core pin insertion hole 43 of the fixed mold body 44 and supported by the seven flange 45a.

The movable mold 50 has a guide bin 51 at the upper end, a movable mold main body 53 having a through hole 52'i in the center for setting the outer shape of the product, and a through hole 52 of the movable mold main body 53. It consists of a capacitance insertion piece (micro pin holder) 54 provided at the bottom of the holder, and a micro pin 55 supported by this capitization insertion piece 54.

The fixed mold 40 and movable mold 50 thus constructed are combined as shown in FIG. 1, set in a molding machine, and a molten material 60 for molding is injected into the injection port 41 from this cylinder. Then, the molten material 60 for molding first flows through the cavity formed by the through hole 52 and the core girder 45 and reaches the bottom of the cavity.

However, in the state shown in FIG. 1, by further injecting the molten material 60 for molding from the cylinder into the injection port 41, there is no place for the molten material 60 to escape, and the pressure of the molten material 60 causes the core bin 45 to The tip (bottom) is pressed,
The core bin 45 is pushed upward and finally becomes as shown in FIG.

Since the core bin 45 is pushed upward by the pressure of the molten material 60 for molding, the body of the ferrule, which is a molded product, has only micro holes (for example, holes with a diameter of 125 μm) formed by the micro pins 55, and 7. The lower half of the collar of the ferrule has only a small hole made by the micro pin 55, and the upper half of the collar of the ferrule has only a hole (a hole with a diameter of 1 m, for example) made by the core bin 45. Therefore, the wall thickness is thicker than that of a ferrule made from a conventional mold, which increases the overall mechanical strength and also increases the mechanical strength of the base of the collar. Therefore, breakage of the ferrule is reduced. Also, core bin 4
5, the apparent protrusion length of the micro pins 55 gradually increases, and the micro pins 55 are not deformed by the pressure when the molten material 60 for molding is injected.

Further, since the weld line formed by the merging of the molten material 60 injected from the injection port 41 is not formed at the tip of the seven errules, a decrease in mechanical strength at this point can be prevented.

〔Effect of the invention〕

According to the present invention described above, since the core pin is slidably provided in the stationary mold body, it is possible to provide a molding die that increases the mechanical strength of the molded product.

[Brief explanation of the drawing]

1 and 2 are both cross-sectional views of an embodiment of a molding die according to the present invention, with FIG. 1 showing the initial state of molding, and FIG. 2 showing the state at the final stage of molding. , FIG. 3 is a sectional view showing a schematic configuration of an optical connector, and FIGS. 4 and 5 are sectional views showing an example of a conventional molding die for manufacturing the ferrule shown in FIG. The figure shows the state before molding, and FIG. 5 shows the state after molding. 40... Fixed mold, 41... Inlet, 42... Guide hole, 43... Core pin insertion hole, 44... Fixed mold body, 45... Core pin, 45a... Flange ,
50 - Movable mold, 51... f-id pin, 52...
Through hole, 53...Movable mold body, 54...Capity insertion piece (micro pin holder), 55...Minute pin. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure M3 Figure 5

Claims (1)

[Claims] An injection port for molten material for molding is formed in the fixed mold body, and a fixed mold is provided with a core pin for setting the inner shape of the product in the fixed mold body, and the mold is movable when combined with this fixed mold. In a molding mold consisting of a movable mold in which the core pin is inserted into the mold body and a hole is formed for setting the outer shape of the product, the core pin is slidably provided in the fixed mold body. . A molding die in which the core pins are sequentially slid upward by the pressure of the molten material during molding.