JP3571796B2 - Molding method - Google Patents

Description

[0001]
[Industrial applications]
The present invention mainly relates to a method of forming a ferrule for an optical connector.
[0002]
[Prior art]
An optical component made of a synthetic resin, for example, a round single-core ferrule for an optical connector (hereinafter simply referred to as a “ferrule”) is usually formed using two dies as follows.
Here, one of the molds is formed with a columnar concave portion and a pin hole connected to the concave portion. A molding pin for forming a fiber hole is attached to the other mold.
[0003]
Then, a ceramic cylindrical body serving as a reference outer mold of the ferrule is inserted into the cylindrical concave portion of the one mold, and the molding pin is positioned in a pin hole while being inserted into the cylindrical body, and both molds are positioned. Close the mold.
In this way, a round ferrule is formed by injecting and solidifying the synthetic resin into the cavity formed by the cylindrical body, the forming pin, and the two dies.
[0004]
At this time, in order to set the cylindrical body into one mold and take out the molded ferrule from the mold, the diameter of the cylindrical concave portion is set slightly larger than the diameter of the cylindrical body, and Care is taken so that a gap of about several μm is formed when the body is inserted.
Also, the diameter of the pin hole is set to be several μm larger than the diameter of the molding pin in order to insert the molding pin into the pin hole when closing the mold or to pull out the pin hole when opening the mold.
[0005]
[Problems to be solved by the invention]
By the way, as described above, if the diameter of the cylindrical concave portion is set slightly larger than the diameter of the cylindrical body and the diameter of the pin hole is set slightly larger than the diameter of the forming pin, the following problem occurs. Was.
That is, the ferrule is originally very small with a diameter of about 2.5 mm and a length of about 14 mm. For this reason, if the positioning of the cylindrical body and the molding pin is not performed with high precision in the molding of the ferrule, the center of the cylindrical body and the center of the fiber hole in the molded ferrule are shifted. As a result, connection loss between optical connectors manufactured using such ferrules varies greatly, and a problem arises in reliability.
[0006]
The present invention has been made in view of the above points, and it is possible to minimize the deviation between the axial center of the ferrule to be molded and the center of the fiber hole as much as possible, and it is excellent in the reliability of the manufactured optical connector. An object of the present invention is to provide a molding method capable of molding a ferrule.
[0007]
[Means for Solving the Problems]
To achieve the above object, according to the present invention, in one set of mold for molding a connector optical ferrule, insert the circular cylindrical body made of a non-criterion type of the connector optical ferrule, of the circular cylinder in the molding method by disposing the molding pins for forming the fiber hole in the hollow portion to form the connector optical ferrule from a synthetic resin, and integrally provided corresponding to the forming pin and the circular cylinder into the mold presses positioned concentrically with the pressing member with respect to the V-groove leading to the molding method for molding the connector ferrule is provided.
[0009]
[Action]
The pressing member positions the cylindrical body and the forming pin in the respective V-grooves with high accuracy.
In the round ferrule formed by the above-described forming method, the center of the outer reference die , that is, the axial center of the ferrule and the center of the fiber hole are positioned with high precision .
[0011]
【Example】
Hereinafter, an embodiment of the forming method of the present invention will be described in detail with reference to FIGS. 1 to 5 based on a ferrule forming apparatus to which the method of the present invention is applied.
A ferrule forming apparatus (hereinafter, referred to as a “forming apparatus”) 1 includes a fixed mold 10 and a movable mold 20 as shown in FIG.
[0012]
The fixed mold 10 has a mold plate 11, a backing 12 and a molding die 13, and a molding pin 14 is attached to the molding die 13.
The template 11 holds a molding die 13 via a backing 12 in a concave portion 11a as shown in the figure. 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 part for molding the rear side of the ferrule, and has an insertion hole 13a for the molding pin 14 in the center and a concave portion 13b formed in a step shape on the lower surface.
[0013]
The forming pin 14 has a shaft portion 14a and a pin portion 14b having a small diameter (0.125 μm in diameter), and is fixed to the forming die 13 at an end of the shaft portion 14a. Projecting from Here, as a synthetic resin used for molding the ferrule, for example, there is an epoxy resin or the like.
The movable mold 20 includes a mold plate 21, a backing 22, a V-groove member 23, a pressing member 24, a molding die 25, and an actuator 26. The mold is opened.
[0014]
As shown in the drawing, the V-groove member 23, the pressing member 24, and the molding die 25 are housed in the recess 21a via the backing 22 as shown in the drawing, and the actuator 26 is arranged in the recess 21b. The backing 22 has a hole 22a formed in the center.
The V-groove member 23, together with the pressing member 24, positions the pin portion 14b of the forming pin 14 and the cylindrical body 6 described later. As shown in FIG. 2, the V-groove member 23 has a positioning groove 23a for positioning the cylindrical body 6 in the center, and a block-shaped positioning portion 23b is integrally formed in the positioning groove 23a. The positioning portion 23b is formed with a V-groove 23c for positioning the pin portion 14b of the forming pin 14. Here, the positioning groove 23a has a rectangular bottom portion and a V-shaped upper portion in a cross-sectional shape in the width direction (see FIG. 4).
[0015]
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. As shown in FIG. 1, a gap G is formed between the pressing member 24 and the block 27 so that the pressing member 24 can retreat toward the actuator 26.
The molding die 25 has an insertion hole 25a through which the cylindrical body 6 is inserted in the center, a step 25b formed slightly adjacent to the insertion hole 25a, and a runner 25c having a slightly larger diameter. The distal end of the shaft of the actuator 26 fed from the main body is connected to the pressing member 24.
[0016]
Here, the cylindrical body 6 is, for example, a ceramic member having a diameter of 2.5 mm, and is 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 formed. It is properly positioned in the recess formed.
The molding method of the present invention is performed as follows when ferrule molding is performed using the molding apparatus 1 configured as described above.
[0017]
First, in the molding apparatus 1 shown in FIG. 1, the actuator 26 is operated to move the pressing member 24 backward by the gap G.
Next, the cylindrical body 6 is inserted into a concave portion formed by the positioning groove 23a of the V-shaped groove member 23, the positioning groove 24a of the pressing member 24, and the insertion hole 25a of the molding die 25.
Next, the movable mold 20 is raised by the driving means (not shown), and is clamped to the fixed mold 10 as shown in FIG. At this time, the pin portion 14 b of the molding pin 14 is inserted into the cylindrical body 6 with the rise of the movable mold 20, and the tip is disposed in the V groove 23 c of the V groove member 23. In parallel with this operation, the actuator 26 is reversely operated, and the pressing member 24 is pushed out. As shown in FIG. 4, the cylindrical body 6 is moved by the positioning grooves 23a, 24a to form the pressing member 24 and the V groove 23c of the V groove member 23. Thus, the pin portions 14b are positioned and fixed with high precision in the order of submicrons. Here, the pressing member 24 is not shown in FIG.
[0018]
Thereby, as shown in the figure, a cavity for molding the ferrule is formed by the molding die 13, the molding die 25, the V-groove member 23, the pressing member 24, and the cylindrical body 6.
Thereafter, a synthetic resin is injected into the cavity from the runner 25c, and after the synthetic resin is cured, the movable mold 20 is lowered by the driving means and opened with respect to the fixed mold 10. At this time, as the movable mold 20 moves down, the pin portion 14b of the molding pin 14 is pulled out of the molded ferrule.
[0019]
Next, the pressing member 24 is retracted by the gap G by the actuator 26, and the formed ferrule is taken out of the movable mold 20.
At this time, as shown in FIG. 5, the formed ferrule 5 has a front-side outer periphery surrounded by a cylindrical body 6, and the inside and the rear side of the cylindrical body 6 are formed of a synthetic resin. Is aligned with the center of the axis with high accuracy. The fiber hole 5a is formed by the pin portion 14b of the forming pin 14.
[0020]
Then, after molding, the ferrule 5 is bonded by inserting the distal end of the optical fiber into the fiber hole 5a and polishing the butted end surface 5b on the front surface by micro lapping or the like to be processed into an optical connector.
Thereafter, the subsequent ferrule molding is performed in the same manner as described above.
Here, in the above-described embodiment, ceramic is used as the material of the cylindrical body 6, but it is needless to say that the material is not limited to this. For example, metal, glass, or the like may be used.
[0021]
In the above embodiment, the ferrule 5 has the cylindrical body 6 on the tip side. However, the entire ferrule may be formed of a synthetic resin. In this case, the movable mold 30 shown in FIG. Use
That is, the movable mold 30 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 is moved up and down by driving means (not shown). The mold is clamped or opened with the fixed mold 10.
[0022]
At this time, the V-groove member 33 and the pressing member 34 are formed with V-groove-shaped positioning grooves 33a and 34a for positioning the cylindrical body 38 and V-grooves 33b and 34b for positioning the pin portion 14b of the forming pin 14. . The molding die 35 has an insertion hole 35a for inserting the pin portion 14b in the center, and a runner 35b on the upper surface. The cylindrical body 38 is a member corresponding to the cylindrical body 6 of the ferrule to be formed.
[0023]
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 denoted by the corresponding reference numerals in FIG. Description is omitted.
Therefore, by the same operation as described above using the movable mold 30, the fiber hole coincides with the axial center with high precision, and a ferrule entirely formed of synthetic resin can be formed.
[0024]
【The invention's effect】
As apparent from the above description, according to the molding method of the present invention, it is possible to the center of the shaft center of the fiber holes of the ferrule to be molded to match the high precision positioning using V-grooves, reliable a round ferrule for superior optical connector sexual can and child molding.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of a molding apparatus to which a molding method according to 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 device of FIG.
FIG. 3 is a cross-sectional view of a state where the molding apparatus of FIG. 1 is clamped.
FIG. 4 is a side view showing a relationship between a cylindrical body positioned by a V-groove member shown in FIG. 2 and a forming pin.
FIG. 5 is a perspective view of a ferrule formed by the forming apparatus of FIG. 1;
FIG. 6 is a sectional view showing another modified example of the movable mold from the front.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Forming apparatus 6, 38 Cylindrical body 10 Fixed mold 11 Mold plate 12 Backing 13 Mold 14 Molding pin 20, 30 Movable mold 21, 31 Mold plate 22, 32 Backing 23, 33 V-groove member 24, 34 Press member 25 , 35 Mold 26,36 Actuator 27,37 Block

Claims (1)

In one set of mold for molding a connector optical ferrule, place the molding pin insert a circular cylindrical body serving as a reference outer die of the connector optical ferrule to form a fiber hole in the hollow portion of the circular cylindrical body And molding the optical ferrule for the connector with synthetic resin,
Characterized in that to V groove continuing the molding pin and the circular cylindrical body and integrally provided in correspondence with the said mold is pressed positioned concentrically with the pressing member, molding the connector ferrule Molding method.

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