JPH06103365B2 - Optical fiber ferrule manufacturing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for manufacturing a ferrule (optical fiber ferrule) for an optical fiber connector made by resin molding.

(Prior Art) A conventional optical connector is, for example, as shown in FIG. 3, a core element insertion hole 2 into which an optical fiber core wire 1 is inserted and a micro element of 125 μm into which an optical fiber element wire 3 is inserted. It is composed of a ferrule 5 having a wire insertion hole 4, a sleeve 6 provided on the outer periphery of the ferrule 5, and a cap nut 7 connecting the sleeve 6 and the ferrule 5.

As shown in FIG. 4, the ferrule 5 is molded with a molding die including a fixed die 10 and a movable die 20. The fixed mold 10 has a fixed mold body 14 having a molding resin injection port 11, a guide hole 12 and a core pin insertion hole 13, and is fixedly inserted into the core pin insertion hole 13 of the fixed mold body 14 and protrudes downward. And a core pin 15 having a minute pin insertion hole 16 at its lower end surface. The movable mold 20 includes a movable mold body 11 having a cylindrical hole 21 and a guide pin 24 opened upward for setting the outer shape of the ferrule 5, and the body 22.
It is composed of a cavity insertion piece (micro pin holder) 23 provided at the bottom of the cylindrical hole 21 and a micro pin 25 which is set in the cavity insertion piece 23 and can be inserted into the micro pin insertion hole 16 of the core pin 15. .

In order to mold the optical fiber ferrule 5 using the molding die having such a configuration, the fixed mold 10 and the movable mold 20 are combined as shown in FIG. 5, and this is set in the molding machine. The molten resin 30 may be injected into the molding resin injection port 11 from the cylinder. By doing so, the resin 30 is gradually injected from the upper part to the lower part of the cavity (space) formed by the hole 21 of the movable mold body 22 and the core pin 15, but finally near the minute pin 25. Since the resin 30 injected into the cylinder has stayed at the tip of the cylinder for a long time, it is deteriorated and its physical property values are lowered. In addition, air in the cavity and bubbles such as gas generated from the resin 30 lose the escape area, and the resin remains in the vicinity of the minute pin 25 and remains.
In the ferrule 5 that is the final product when 30 is cooled, variations in the diameter of the micro hole (element wire insertion hole 4) at the most important tip portion and the outer dimensions of this portion are likely to occur, There is a problem that the surface tends to be rough.
In addition, since a weld line formed by the joining of the divided resin flows is formed at the tip of the ferrule 5, there is a problem that it becomes a cause of lowering the mechanical strength of this portion.

Further, although the conventional optical fiber ferrule is manufactured by resin molding as described above, there is also a problem that the mechanical strength of the optical fiber ferrule cannot be increased so much because the strength of the resin itself is not so high.

(Object of the Invention) In view of the above problems, an object of the present invention is to provide an apparatus for manufacturing an optical fiber ferrule having high mechanical strength. In particular, this manufacturing apparatus can reduce variations in the diameter of the wire insertion hole that receives and holds the optical fiber wire in the optical fiber ferrule and in the outer dimensions of this portion, and that this wire insertion hole is formed. It is also an object of the present invention to make the outer surface roughness of the tip portion to be fine and to prevent deterioration of the mechanical strength of this portion.

(Example) Hereinafter, an optical fiber ferrule manufacturing apparatus according to the present invention will be described with reference to FIG.

As shown in FIG. 1, this manufacturing apparatus mainly includes a fixed mold 40, a movable mold 50, and a hollow cylindrical sleeve 60. The fixed mold 40 has a plurality of injection ports 41 for molding molten resin, a guide hole 42, and a core pin insertion hole 43, and the core pin 45 is attached to the core pin insertion hole 43 while protruding downward. .

The core pin 45 has a cylindrical shape and has a flange 45a at the upper end.
Is formed, and a minute pin insertion hole 43b is formed at the lower end. The core pin 45 is inserted and fixed in the core pin insertion hole 43 of the fixed mold body 44.

The movable mold 50 has a guide pin 51 at the upper end, and a movable mold body 53 having a through hole 52 for setting the cylindrical outer shape of the optical fiber ferrule at substantially the center, and the movable mold body 53. A cavity insertion piece (micro pin holder) 54 attached to the bottom of the through hole 52 of 53 by closing the through hole 52,
It is composed of minute pins 55 supported by the cavity insertion piece 54.

A hollow cylindrical sleeve 60 of a hollow cylinder formed of a hard material such as metal (for example, stainless steel), ceramics, or glass is arranged on the outer periphery of the core pin 45, and when required for the fixed mold body 44 ( That is, it is detachably attached so that it can be removed when the ferrule is taken out after molding.

As shown in the drawing, the inner diameter of the hollow cylindrical sleeve 60 is larger than the outer diameter of the core pin 45, and the outer diameter of the hollow cylindrical sleeve 60 is smaller than the inner diameter of the through hole 52. Therefore, a cylindrical inner space extending vertically is formed between the inner peripheral surface of the hollow cylindrical sleeve 60 and the outer peripheral surface of the core pin 45, and the outer peripheral surface of the hollow cylindrical sleeve 60 and the inner periphery of the through hole 52 are formed. A cylindrical outer space extending vertically is also formed between the surface and the surface. The inner space and the outer space communicate with each other at the lower end.

The fixed mold 40 and the movable mold 50 configured in this way,
With the hollow cylindrical sleeve 60 attached to the fixed mold 40, the core pin 45 (and the hollow cylindrical sleeve 60) is projected into the through hole 52, and the core pin 45 (and the hollow cylindrical sleeve 60) is combined as shown in FIG. Set it on the machine. Then, the molding molten resin 70 is gradually and simultaneously injected from the plurality of injection ports 41 little by little from the cylinder of the molding machine.

Then, the molten resin for molding 70 is first of all the hollow cylindrical sleeve.
It is injected into the upper part of a cylindrical outer space formed by extending vertically between the outer peripheral surface of 60 and the inner peripheral surface of the through hole 52, and flows from the upper part of the outer space to the lower part. When the bottom of the outer space (that is, the bottom surface of the cavity) is reached, an inner space communicating at the bottom (a cylinder formed vertically extending between the inner peripheral surface of the hollow cylindrical sleeve 60 and the outer peripheral surface of the core pin 45). Shaped inner space), flows upward in this inner space, and when reaching the upper end of the inner space, the entire space (cavity) is filled with the injected resin.

When the molten resin flows in this manner, the molten resin stays in the cylinder for a long time, and the deterioration of the molten resin causes the physical properties of the molten resin to decrease, so that the molten resin flows into the upper portion of the inner space. Therefore, in the lower part (the part where the minute pins 55 are exposed and where the outer space and the inner space communicate with each other), which is the most problematic in the optical fiber ferrule molded in this way, deterioration progresses and physical property values are increased. The lowered molten resin does not remain. For this reason, there is little variation in the diameter of the element wire insertion hole 4 of the ferrule formed by the minute pin 55, and the roughness of the outer surface of this portion, that is, the tip of the ferrule becomes fine.

Furthermore, since the weld line formed by the merging of the molten resin 70 injected from the injection port 41 can be formed in the upper part of the inner space (that is, the rear end part of the ferrule) and is not formed at the tip part of the ferrule, the wire insertion hole 4 is formed. It is possible to prevent the strength of the formed tip portion from decreasing.

Then, after the resin 70 injected in this way has cooled and hardened, the movable mold 50 is separated from the fixed mold 40, and the ferrule 80 in a state in which the hollow cylindrical sleeve 60 is embedded inside the mold. When taken out, the ferrule 80 according to the present invention as shown in FIG. 2 can be obtained. In the ferrule 80, as shown in the drawing, the rear end portion 60a (the portion attached to the fixed mold 40) of the hollow cylindrical sleeve 60 embedded in the resin body 81 is separated from the rear portion 81a of the body 81. The rear end portion 60a may be cut because it projects rearward.

The optical fiber ferrule 80 manufactured in this way is
The core wire insertion hole 82 formed by the core pin 45 and the minute pin
And a wire insertion hole 83 formed by 83. In addition, while inserting the optical fiber core wire 1 into the core wire insertion hole 82,
The ferrule 80 is attached to the tip of the optical fiber by inserting the optical fiber strand 3 into the strand insertion hole 83.

This optical fiber ferrule 80 has a hollow cylindrical sleeve 60 made of a hard material embedded therein,
The ferrule 80 has high mechanical strength, and in particular, the root of the brim of the ferrule 80 is less likely to be broken.

Further, in the manufacturing apparatus shown in FIG. 1, since the core pin 45 and the hollow cylindrical sleeve 60 are attached to the fixed mold 40, the mold structure is simple.

In the above embodiment, the injection port for the molding molten resin 70 is formed in the fixed mold body 44, but it may be configured so as to inject the resin 70 from the upper part of the outer space. It may be formed on the upper part of the mold body 53.

(Effects of the Invention) As described above, in the optical fiber ferrule manufacturing apparatus of the present invention, when the first mold (movable mold) and the second mold (fixed mold) are combined, Hollow cylinder attached to the second mold by the core pin projecting concentrically into the cylindrical hole, the lower end of which separates from the bottom of the cylindrical hole, and the tip of the minute pin is inserted into the minute pin insertion hole formed at the lower end of the core pin. -Shaped sleeve also thrusts concentrically into the cylindrical hole,
Its lower end is configured to be separated from the bottom surface of the cylindrical hole by a predetermined distance.

Therefore, in this manufacturing apparatus, in a state where the first mold and the second mold are combined, the inner peripheral surface of the cylindrical hole and the outer peripheral surface of the hollow cylindrical sleeve are inserted from the injection port formed in the second mold. If molten resin is injected into the space surrounded by the space, the resin flowing from the upper part to the lower part of this space will pass through the space between the lower end of the hollow cylindrical sleeve and the bottom of the cylindrical hole, and inside the hollow cylindrical sleeve. It flows in the space surrounded by the peripheral surface and the outer peripheral surface of the core pin.

In this case, in the vicinity of the lower end of the hollow cylindrical sleeve, that is, in the portion where the fine pin is provided and the wire insertion hole is formed, the resin that has been initially injected and deteriorated does not remain,
Also, no weld line is formed in this portion. Therefore, the physical properties of the resin in this portion are good,
High strength. Therefore, by using this manufacturing apparatus, it is possible to manufacture an optical fiber ferrule having a small variation in the diameter of the wire insertion hole, a fine roughness on the outer surface of this portion, and a sufficient strength.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a ferrule manufacturing apparatus according to the present invention, FIG. 2 is a cross-sectional view showing an optical fiber ferrule according to the present invention and an optical fiber to which the ferrule is attached, and FIG. FIG. 4 is a cross-sectional view showing a state in which fibers are connected, and FIGS. 4 and 5 are cross-sectional views showing a conventional ferrule manufacturing apparatus. 40 …… Fixed die, 41 …… Injection port 43 …… Core pin insertion hole, 44 …… Fixed die body 45 …… Core pin, 50 …… Movable die 53 …… Movable die body, 55 …… Small pin 60 …… Hollow cylindrical sleeve

Front Page Continuation (72) Inventor Masao Ozaki 9-52, 1-52, Shibasaki, Chofu, Tokyo (56) References: Fujisawa Seisakusho Co., Ltd. (56) Reference JP-A-56-11424 (JP, A) JP-A-57- 205706 (JP, A) JP 58-9116 (JP, A) JP 56-38487 (JP, Y2)

Claims (1)

[Claims] 1. A core wire insertion hole (82) formed by opening at one end side for inserting an optical fiber core wire (1) and this core wire insertion hole for inserting an optical fiber element wire (3). A device for manufacturing an optical fiber ferrule (80) having an element wire insertion hole (83) penetratingly formed in the bottom of the optical fiber ferrule (80), the external shape of the optical fiber ferrule. , A first die (50) having an upwardly opening cylindrical hole (52) and a second die having a downwardly projecting cylindrical core pin (45) corresponding to the shape of the core wire insertion hole. A mold (40), which is formed in a hollow cylindrical shape having an inner diameter larger than the outer diameter of the core pin and an outer diameter smaller than the inner diameter of the cylindrical hole, and is detachably attached to the second mold so as to surround the core pin. A hollow cylindrical sleeve (60) made of a hard material, and Is formed into a linear shape having a diameter corresponding to the shape of the line insertion hole,
The micro pin (55) is attached to the bottom of the cylindrical hole of the first mold so as to project upward, and when the first mold and the second mold are combined, the core pin is The hollow cylindrical sleeve attached to the second mold also projects concentrically into the cylindrical hole, the lower end thereof is separated from the bottom surface of the cylindrical hole, and the tip of a minute pin formed at the lower end of the core pin is inserted. The hollow cylindrical shape and the hollow cylindrical shape projecting concentrically into the cylindrical hole, the lower end of which is separated from the bottom surface of the cylindrical hole by a predetermined distance, and which is surrounded by the inner peripheral surface of the cylindrical hole and the outer peripheral surface of the hollow cylindrical sleeve. The space surrounded by the inner peripheral surface of the sleeve and the outer peripheral surface of the core pin is configured to be connected only through the space between the lower end of the hollow cylindrical sleeve and the bottom surface of the cylindrical hole, In a state where the first mold and the second mold are combined, the inner peripheral surface of the cylindrical hole and the inner peripheral surface of the cylindrical hole are inserted through the injection port (41) formed in the upper part of the first mold or the second mold. Molten resin is injected from the upper part of the space surrounded by the outer peripheral surface of the hollow cylindrical sleeve, and the resin flowing from the upper part of the space to the lower part is injected between the lower end of the hollow cylindrical sleeve and the bottom of the cylindrical hole. The hollow cylindrical sleeve is made to flow through the space into the space surrounded by the inner peripheral surface of the hollow cylindrical sleeve and the outer peripheral surface of the core pin to manufacture an optical fiber ferrule in which the hollow cylindrical sleeve is embedded inside a resin body. An optical fiber ferrule manufacturing apparatus characterized by the above.