JPH08290483A - Molding method - Google Patents

Abstract

PURPOSE: To provide a molding method which can control a deviation between an axial center of a ferrule to be molded and a center of fiber hole to be as small as possible and mold the ferrule of superior reliability of an optical connector to be manufactured. CONSTITUTION: A casing 6 forming a reference outer mold of an optical part is inserted into a set of molds 10 and 20 for molding an optical part, and a core 14 is disposed in a hollow section of the casing and the optical part is molded by a synthetic resin in the molding method. The optical part is molded while positioning is carried out by positioning means 23 and 24 on which positioning sections of the dimensions corresponding to the casing 6 and the core 14 respectively are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method for molding a ferrule for an optical connector.

[0002]

2. Description of the Related Art Optical parts made of synthetic resin, for example, a round single-core ferrule for an optical connector (hereinafter simply referred to as "ferrule")
Is usually molded in the following manner using two molds. Here, in one of the molds, a columnar concave portion and a pin hole continuous with the concave portion are formed. A molding pin for forming a fiber hole is attached to the other mold.

Then, a ceramic cylindrical body serving as a non-standard ferrule mold is inserted into the cylindrical concave portion of the one mold, and the molding pin is positioned by a pin hole while being inserted into the cylindrical body. Clamp both dies. In this manner, the synthetic resin is injected into the cavity formed by the cylindrical body, the molding pin, and the two dies, and is solidified, whereby the round ferrule is molded.

At this time, the diameter of the cylindrical recess is set to be slightly larger than the diameter of the cylindrical body in order to set the cylindrical body in one of the molds and take out the molded ferrule from the mold. Therefore, it is considered that a gap of about several μm is formed when the cylindrical body is inserted. Further, the diameter of the pin hole is set to be larger than the diameter of the molding pin by about several μm in order to insert the molding pin into the pin hole at the time of mold clamping or pull out from the pin hole at the time of mold opening.

[0005]

By the way, as described above, the diameter of the cylindrical recess is slightly larger than the diameter of the cylindrical body, and the diameter of the pin hole is slightly larger than the diameter of the molding pin. When set, there were the following problems. That is, originally, the ferrule has a diameter of about 2.5 mm and a length of 14 mm.
It is a very small size of about mm. For this reason, in the molding of the ferrule, unless the cylinder and the molding pin are accurately positioned, the center of the cylinder and the center of the fiber hole will be displaced in the molded ferrule. As a result, the connection loss between the optical connectors manufactured by using such ferrules greatly varies, which causes a problem in reliability.

The present invention has been made in view of the above points, and it is possible to suppress the deviation between the axial center of the molded ferrule and the center of the fiber hole as small as possible, and the reliability of the optical connector to be manufactured. An object of the present invention is to provide a molding method capable of molding an excellent ferrule.

[0007]

According to the present invention, in order to achieve the above object, a cylindrical body serving as an out-of-reference mold of the optical component is inserted into a set of molds for molding the optical component, In a molding method of arranging a core in a hollow portion of a tubular body and molding an optical component with a synthetic resin, while positioning the tubular body and the core by a positioning means having positioning portions of corresponding sizes, respectively. The optical component is molded.

[0008] Preferably, the optical component is a ferrule for an optical connector. Further, preferably, the cylindrical body is a cylinder. More preferably, the core is a molding pin that forms a fiber hole. Preferably, the positioning means is V
The groove.

[0009]

The positioning means positions the cylinder and the core with high accuracy at the positioning portion. At this time, if the optical component is a ferrule for an optical connector, the center of the non-standard mold of the optical component and the center of the core of the molded ferrule coincide with each other with high accuracy. Further, when the cylindrical body is a cylinder, a round ferrule is molded.

Further, when the core is a molding pin for forming a fiber hole, the axial center of the ferrule and the center of the fiber hole coincide with each other with high accuracy. When the positioning means is a V groove, the positioning accuracy is dramatically improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the molding method of the present invention will be described in detail below with reference to FIGS. 1 to 5 based on a ferrule molding apparatus to which the method of the present invention is applied. The ferrule molding apparatus (hereinafter referred to as “molding apparatus”) 1 includes a fixed mold 10 and a movable mold 20, as shown in FIG.

The fixed mold 10 includes a mold plate 11 and a backing 1.
2 and a molding die 13, and the molding die 13 includes a molding pin 1
4 is attached. The template 11 is, as shown,
The mold 13 is held in the recess 11a via the backing 12. The backing 12 has a recess 12a formed in the center, and the upper end of the molding pin 14 is housed in the recess 12a. The molding die 13 is a portion for molding the rear side of the ferrule, and has an insertion hole 13a for the molding pin 14 formed in the center and a stepped recess 13b formed on the lower surface.

The molding pin 14 has a shaft 14a and a small diameter (diameter).
0.125 μm) of the pin portion 14b, and the shaft portion 14
It is fixed to the molding die 13 at the end of a, and the pin portion 14b projects from the lower surface of the molding die 13. Here, the synthetic resin used for molding the ferrule includes, for example, an epoxy resin. The movable mold 20 includes a mold plate 21 and a backing 2
2. It has a V groove member 23, a pressing member 24, a molding die 25 and an actuator 26, and is moved up and down by a driving means (not shown) to be clamped or opened with the fixed mold 10.

As shown in the figure, the template 21 has a V-groove member 23, a pressing member 24 and a molding die 25 housed in a recess 21a through a backing 22, and an actuator 26 is disposed in the recess 21b. The backing 22 has a hole 2 in the center.
2a is formed. The V groove member 23 is a pressing member 24.
At the same time, the pin portion 14b of the molding pin 14 and the cylindrical body 6 described later are positioned. As shown in FIG. 2, the V-shaped groove member 23 has a positioning groove 23a for positioning the cylindrical body 6 formed in the center thereof, and a block-shaped positioning portion 23b is integrally formed with the positioning groove 23a. The positioning portion 23b has a V groove 2 for positioning the pin portion 14b of the molding pin 14.
3c is formed. Here, the positioning groove 23a is
In the cross-sectional shape in the width direction, the bottom is rectangular and the top is V-shaped (see FIG. 4).

The pressing member 24 has a substantially similar positioning groove 24a formed at a position corresponding to the positioning groove 23a of the V groove member 23 for positioning the cylindrical body 6. Pressing member 24
As shown in FIG. 1, a gap G is formed between the block 27 and the block 27 so as to be able to retract toward the actuator 26 side. The molding die 25 is formed with an insertion hole 25a through which the cylindrical body 6 is inserted, a stepped portion 25b and a runner 25c which are adjacent to the insertion hole 25a and have a slightly larger diameter. The actuator 26 is connected to the pressing member 24 at the tip of a shaft that is extended from the main body.

Here, the cylindrical body 6 has a diameter of 2.5 m, for example.
The ceramic member m is properly positioned in the recess formed by the positioning groove 23a of the V groove member 23, the positioning groove 24a of the pressing member 24, and the insertion hole 25a of the molding die 25 when the ferrule is molded. The molding method of the present invention is executed as follows when ferrule molding is performed using the molding apparatus 1 configured as described above.

First, in the molding apparatus 1 shown in FIG. 1, the actuator 26 is actuated to move the pressing member 24 into the gap G.
Move back by the amount of. Next, the positioning groove 23a of the V groove member 23, the positioning groove 24a of the pressing member 24, and the molding die 2
The cylindrical body 6 is inserted into the concave portion formed by the insertion hole 25 a of No. 5. Next, the movable mold 20 is raised by the driving means (not shown), and as shown in FIG.
Clamp to 0. At this time, the pin portion 14 b of the molding pin 14 is inserted into the cylindrical body 6 as the movable mold 20 is raised, and the tip end thereof is arranged in the V groove 23 c of the V groove member 23. In parallel with this operation, the actuator 26 is reversely actuated and the pressing member 24 is pushed out, and as shown in FIG. 4, the cylindrical body 6 is positioned by the positioning grooves 23a and 24a, and the pressing member 24 and the V groove 23c of the V groove member 23. The pin portions 14b are positioned and fixed with high precision on the order of submicrons by and. Here, the pressing member 24 is not shown in FIG.

Thus, as shown in the drawing, the mold 1
3, the molding die 25, the V groove member 23, the pressing member 24, and the cylindrical body 6 form a cavity for molding the ferrule. Then, a synthetic resin is injected into the cavity from the runner 25c, and after the synthetic resin is hardened, the movable mold 20 is lowered by the driving means to open the mold with respect to the fixed mold 10. At this time, as the movable mold 20 descends, the pin portion 14b of the molding pin 14 is pulled out from the molded ferrule.

Next, the actuator 26 moves the pressing member 24 back by the gap G, and the molded ferrule is taken out of the movable mold 20. At this time, as shown in FIG. 5, the molded ferrule 5 has the outer periphery on the front side surrounded by the cylindrical body 6, and the inside and the rear side of the cylindrical body 6 are molded with the synthetic resin. The fiber hole 5a extending to the position coincides with the axis center with high accuracy. Fiber hole 5
A is formed by the pin portion 14b of the forming pin 14.

After molding the ferrule 5, the tip end side of the optical fiber is inserted into the fiber hole 5a and adhered thereto, and the butt end surface 5b on the front surface is polished by micro-lapping or the like to be processed into an optical connector. The subsequent molding of the ferrule is performed in the same manner as described above. Here, although ceramic is used as the material of the cylindrical body 6 in the above embodiment, it is needless to say that the material is not limited to this, and for example, metal, glass or the like may be used.

In the above embodiment, the ferrule 5 has the cylindrical body 6 on the distal end side. However, the entire ferrule may be molded of synthetic resin, and in this case, it is movable as shown in FIG. A mold 30 is used. That is, the movable mold 3
Reference numeral 0 has a mold plate 31, a backing 32, a V groove member 33, a pressing member 34, a molding die 35, an actuator 36, a block 37, and a cylindrical body 38. And clamp or open the mold.

At this time, the V groove member 33 and the pressing member 34
Is a V-groove-shaped positioning groove 33 for positioning the cylindrical body 38.
a and 34a and V grooves 33b and 34b for positioning the pin portion 14b of the molding pin 14 are formed. Mold 35
Has a through hole 35a at the center for inserting the cylindrical body 38, and a runner 35b at the upper surface. The cylindrical body 38 is a member for molding a portion of the ferrule to be molded corresponding to the cylindrical body 6.

In the template 31, the backing 32, the actuator 36, the block 37 and other components, the same components as those of the movable mold 20 are designated by the corresponding symbols in FIG. Therefore, detailed description will be omitted. Therefore, by using the movable mold 30 and the same operation as described above, the fiber hole can be aligned with the axial center with high accuracy, and a ferrule molded entirely of synthetic resin can be molded.

[0024]

As is apparent from the above description, according to the present invention, the deviation between the axial center of the molded ferrule and the center of the fiber hole can be suppressed as small as possible, and the optical connector to be manufactured. It is possible to provide a molding method capable of molding a ferrule having excellent reliability.

At this time, if the optical component is a ferrule for an optical connector, the center of the non-reference mold of the optical component and the center of the core of the molded ferrule can be aligned with high accuracy. Further, if the tubular body is a cylinder, a round ferrule can be molded. Furthermore, if the core is a molding pin that forms a fiber hole, the axial center of the ferrule and the center of the fiber hole can be aligned with high accuracy.

If the positioning means is a V groove, the positioning accuracy can be dramatically improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a molding apparatus to which a molding method of the present invention is applied, as viewed from the front.

FIG. 2 is a perspective view of a V groove member used in the molding apparatus of FIG.

FIG. 3 is a cross-sectional view of a state in which the molding apparatus of FIG. 1 is clamped.

FIG. 4 is a side view showing a relationship between a cylindrical body positioned by the V groove member shown in FIG. 2 and a molding pin.

5 is a perspective view of a ferrule molded by the molding device of FIG. 1. FIG.

FIG. 6 is a sectional view showing another modified example of the movable mold from the front.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding apparatus 6,38 Cylindrical body 10 Fixed mold 11 Mold plate 12 Backing 13 Molding mold 14 Molding pin 20,30 Movable mold 21,31 Mold plate 22,32 Backing 23,33 V groove member 24,34 Pressing member 25 , 35 Mold 26, 36 Actuator 27, 37 Block

Claims (5)

[Claims] 1. A cylindrical body, which serves as an out-of-reference mold for the optical component, is inserted into a set of molds for molding the optical component, a core is arranged in the hollow portion of the cylindrical body, and the optical component is made of synthetic resin. A molding method for molding a component, characterized in that the optical component is molded while positioning the cylindrical body and the core by positioning means having positioning portions of corresponding sizes. 2. The molding method according to claim 1, wherein the optical component is a ferrule for an optical connector. 3. The cylinder according to claim 1, wherein the cylinder is a cylinder.
Molding method. 4. The molding method according to claim 1, wherein the core is a molding pin that forms a fiber hole. 5. The molding method according to claim 1, wherein the positioning means is a V groove.