JP2003287652A - Pin holder and pin holding unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pin holding unit which stably maintains the holding accuracy of a molding pin for an optical fiber insertion hole (micropore) over a long period of time in the resin forming process of a mechanically transferable optical connector ferrule. <P>SOLUTION: The pin holding unit includes the pin holder 5 of a part in which the fiber hole molding pin insertion hole 14 is bored and a fiber hole molding pin 7 inserted into the fiber hole molding pin insertion hole 14 of the pin holder 5 both of which project from a front end surface 12. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pin holder and a pin holding unit for molding an optical component, which is attached to a mold and used when molding an optical component having an optical fiber insertion hole.

[0002]

2. Description of the Related Art FIGS. 10 to 12 show JIS C 59.
81 MT type optical connector ferrule (MT:
1 shows an example of a Mechanically Transferable (hereinafter, optical connector ferrule).
The optical connector ferrule 50 shown in these figures has a fiber insertion opening 51 for inserting an optical fiber 57 (optical fiber tape core wire or the like) into the optical connector ferrule 50, an optical fiber insertion hole 52, and a guide. Pin hole 53
And an adhesive injection window 54 are formed to form a wide rectangular shape, and also has a rectangular flange portion 56 on the side opposite to the joint end surface 55 for connector connection (right side of the paper in FIGS. 5 to 12). It is a plastic molded product. An optical fiber 57 is inserted into the fiber insertion opening 51, and a bare fiber 58 that is exposed at the tip of the optical fiber 57 is inserted into the optical fiber insertion hole 52 and fixed with an adhesive. The numeral 59 shown in FIG. 12 indicates a rubber boot 59 for protecting the mouth of the optical fiber. Code 5
0a is a guide groove.

As shown in FIG. 13, as a mold 60 used for resin molding of the optical connector ferrule 50, an openable / closable mold body composed of an upper mold 63 and a lower mold 64, an optical fiber insertion hole 52 and a guide. Mold parts to which molding pins 66, 67 for forming the pin hole 53 (fiber hole molding pin 66 for molding the optical fiber insertion hole 52, guide pin hole molding pin 67 for molding the guide pin hole 53) are fixed A medium size 65 (hereinafter referred to as “pin holding unit”) is widely used. Reference numeral 62 in FIG. 13 is a gate for injecting the molten resin.

In the illustrated example, a projection 70 for forming the adhesive injection window 54 is formed in the recess 69 of the lower mold 64. The fiber hole forming pin 66 and the guide pin hole forming pin 67 are projected from the pin holding unit 65 in the same direction. In the end wall 64a of the lower die 64, a hole 71 into which the fiber hole forming pin 66 is fitted and a hole 72 into which the guide pin hole forming pin 67 is fitted when the pin holding unit 65 is incorporated in the die body. And are formed.

The upper mold 63 and the lower mold 64 have recesses 68 and 69 which form a cavity between the upper mold 63 and the lower mold 64.
Are formed. It should be noted that when the molded product molded by the mold 60 of FIG. 13 is turned upside down, the state shown in FIG. 12 is obtained. An arrow M1 in FIG. 13 indicates an upper mold 63 with respect to the lower mold 64.
And M2 indicates the sliding movement direction of the pin holding unit 65.

14 and 15 show the fiber hole molding pin fixing portion 61 of the pin holding unit 65.
FIG. 14 is a side view showing the vicinity of the step portion 77 at the tip of the fiber hole molding pin fixing portion 61, and FIG.
The K section is shown. Fiber hole forming pin fixing portion 6
1 has a configuration in which a fiber hole molding pin 66 positioned in a V groove 75 on the lower pin holder structure 74 is sandwiched and fixed (bind structure) between an upper pin holder structure 73 and a lower pin holder structure 74. ing. The upper pin holder structure 73 is provided with a groove 76 having a semicircular cross section which is in close contact with the fiber hole forming pin 66 on the V groove 75. The protruding tip of the upper pin holder structure 73 into the mold is shorter than that of the lower pin holder structure 74, and the fiber hole forming pin 66 is provided in the step portion 77 at the tip of the upper and lower pin holder structures 73, 74. Exposed. The exposed portion of the fiber hole forming pin 66 in the step portion 77 is a portion for forming the guiding groove 50a of the optical connector ferrule 50. Although not shown, the fixing structure of the guide pin forming pin 67 in the pin holding unit 65 is also a structure (binding structure) in which the guide pin forming pin 67 is positioned by a positioning means such as a V groove and sandwiched between two members.

[0007]

By the way, in the above-mentioned conventional pin holding unit 65, when molding the optical connector ferrule 50, a molten resin is formed in a gap between the fiber hole molding pin 66 and the bottom of the V groove 75. Has a problem in that a force that pushes between the upper and lower pin holder structures 73 and 74 acts to give a subtle error to the positioning accuracy of the fiber hole forming pin 66. For this reason, the conventional pin holding unit 65 requires disassembly maintenance accompanied by machine stoppage in order to maintain the holding accuracy of the fiber hole forming pin 66. However, although there is a problem that the accuracy of holding the fiber hole forming pin 66 can be restored by the disassembly maintenance work, there is a problem that the deterioration of accuracy becomes remarkable due to the deterioration of the mold over time. Problems like this
The same applies to the guide pin forming pin 67. Therefore, in order to improve productivity, there has been an urgent need to develop a mold structure that extends the time during which the holding accuracy can be maintained.

In view of the above problems, it is an object of the present invention to provide a pin holder and a pin holding unit capable of stabilizing the holding accuracy of a fiber hole molding pin inserted through a pin holder for molding an optical component for a long period of time. To do.

[0009]

In order to achieve the above object, the present invention proposes the following means. The invention according to claim 1 is a pin holder for forming an optical component, which is used for forming an optical fiber insertion hole by being attached to a mold when forming an optical component having an optical fiber insertion hole, A fiber hole molding pin insertion hole, through which the fiber hole molding pin for forming the optical fiber insertion hole is inserted, is opened in the front end surface on a front wall forming a front end surface of a portion arranged in a protruding state in the mold. It is characterized in that it is perforated.

The fiber hole molding pin insertion hole formed in the pin holder of the present invention has a structure formed in the front wall and does not have the binding structure as in the prior art. Even if it occurs, deformation such as expansion of the fiber hole forming pin insertion hole does not occur, and the holding accuracy of the fiber hole forming pin can be stably maintained. Further, for example, for a fiber hole forming pin having a circular cross section, it is easy to form a shape (inner surface shape) which is in close contact with the fiber hole forming pin by drilling a front wall or the like. Compared with the V-groove described above, the gap between the inserted fiber molding pin can be reduced, and at the time of resin molding of the optical component,
It is possible to effectively prevent the molten resin from entering the fiber hole forming pin insertion hole.

According to a second aspect of the present invention, in the pin holder according to the first aspect, the inclination is inclined with respect to the axis of the fiber hole forming pin insertion hole so that the fiber hole forming pin insertion hole is opened in the front end surface. It is characterized in that a surface is formed.

The inclined surface of the pin holder of the present invention is a portion in which a guide groove is formed in the manufactured ferrule in order to facilitate insertion of an optical fiber (bare fiber or the like) into the optical fiber insertion hole. The configuration in which the guide groove is formed by the inclined surface has an advantage that the guide groove shape can be freely set by the shape of the inclined surface.

According to a third aspect of the present invention, when an optical component having an optical fiber insertion hole is molded, a pin holding for molding an optical component is used which is attached to a mold to form the optical fiber insertion hole. A unit, comprising: the pin holder according to claim 1 or 2, and a fiber hole forming pin inserted into the fiber hole forming pin insertion hole of the pin holder so as to project its tip from the front end face. It is characterized by that.

According to the pin holding unit of the present invention, the accuracy of holding the fiber hole forming pin can be maintained with high accuracy when the optical component is molded with resin. Further, the fiber hole forming pin insertion hole can be effectively prevented from entering the molten resin into the fiber hole forming pin insertion hole by realizing a shape that is in close contact with the fiber hole forming pin.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a pin holder and a pin holding unit according to an embodiment of the present invention, and FIG. 1 is an exploded perspective view showing a mold constituted by using the pin holding unit. 2 is a cross-sectional view of a pin holder that is a part of the pin holding unit. 3 to 7 illustrate a method of manufacturing the pin holder. 8 and 9 are cross-sectional views showing an optical connector ferrule molded by using the mold of FIG. 1, and FIG.
The LL cross section of FIG.

In FIGS. 1 and 2, the pin holding unit 1, the upper mold 2, and the lower mold 3 constitute a resin molding die 4 of the MT type optical connector ferrule. Pin holding unit 1
Functions as an intermediate mold disposed between the upper mold 2 and the lower mold 3, and includes a fiber holder molding pin 7 and a guide pin hole molding pin 8 in a pin holder 5 which is a mold component composed of one component. Is inserted and fixed. The configurations of the upper mold 2 and the lower mold 3 are similar to those of the upper mold 63 and the lower mold 64 shown in FIG.
The same parts as those of FIG. 13 are designated by the same reference numerals.
In FIG. 2, the holder 6 is a member for fixing the fiber pin 7 inserted into the fiber hole forming pin insertion hole 14 of the pin holder 5.

The pin holder 5 is opposed to the holder body 5a, which is a hollow rectangular parallelepiped body, and the tip (on the side of the front end surface 12 (including the inclined surface 11)) projecting into the mold 4 of the holder body 5a. It has a flange portion 9 protruding in a flange shape on the outer periphery of the rear end portion. The internal space 10 of the holder body 5a is
The holder body 5a is a recessed portion that is formed by digging from the rear end side toward the front end surface 12, and has an opening 10a at the rear end side of the holder body 5a.

The front wall 13 forming the front end face 12 passes through the front wall 13 from the internal space 10 and the front end face 1
A fiber hole forming pin insertion hole 14 that opens at 2 is formed. Further, a guiding groove 24 (see FIGS. 8 and 9) inside the optical connector ferrule 21 is formed on the inclined surface 11 formed on the front wall 13 so as to be inclined with respect to the axis of the fiber hole forming pin insertion hole 14. Therefore, the convex portion 15 is formed.

The fiber hole molding pin 7 has a main portion 16 having a circular contour in cross section and extending in one direction, and a small tip portion formed to have a smaller diameter than the main portion 16 and projecting so as to extend the tip portion of the main portion 16. 17 and is fixed to the holder body 5a in a state where the main portion 16 is inserted into the fiber hole forming pin insertion hole 14. The tip small diameter portion 17 is a portion for forming an optical fiber insertion hole 25, for example, a fine hole having a diameter of 126 μm and a low degree, which is opened in the joining end surface 26 (see FIG. 8) of the optical connector ferrule 21, and is projected from the front end surface 12. The main part 16
It is arranged so as to project from the tip. As shown in FIG. 2, the fiber hole molding pin 7 has a convex portion 18 projecting from the rear end side surface of the main portion 16 in a front wall 13 around the fiber hole molding pin insertion hole 14 of the internal space 10. While being engaged from the side, the holding body 6 inserted into the internal space 10 and fixed to the holder body 5a prevents the holder body 5a from slipping out to the rear end side. In the present embodiment, the main portion 16 has a diameter of 250 μm lower, and the tip small diameter portion 17 has a diameter of 1 μm.
It is about 26 μm. Fiber hole forming pin insertion hole 14
Is a round hole having an inner diameter slightly (for example, about several μm) larger than the outer diameter of the fiber hole forming pin 7 having a circular cross section, and here, the inner diameter is about 251 to 252 μm.

On the other hand, two guide pin hole forming pins 8 are provided in the pin holding unit 1, and each guide pin hole forming pin 8 extends to both sides where the collar portion 9 faces the holder body 5a. Pin fixing portions 9a and 9b, which are fixed portions
Guide pin hole that is penetrated into the molding pin insertion hole 20 (hereinafter,
It may be abbreviated as "guide-side pin insertion hole") and supported in parallel with each other. The guide pin hole forming pin 8 fitted in the guide side pin insertion hole 20 is fixed by a fixing component (not shown) on the rear end side of the holder body 5a. The guide-side pin insertion hole 20 is also a round hole having an inner diameter slightly (about several μm) larger than the outer diameter of the guide pin hole forming pin 8 having a circular cross section.

The pair of guide pin hole forming pins 8 are projected from the pin fixing portions 9a and 9b along the holder body 5a, and between the pair of guide pin hole forming pins 8 the front end surface of the holder body 5a. A plurality of fiber hole forming pins 7 protruding from 12 are arranged side by side. The guide pin hole forming pin 8 and the fiber hole forming pin 7 provided in this pin holding unit are positioned with high precision so as to be parallel to each other.

Next, an example of a method for forming the pin holder 5 will be described with reference to FIGS. First, as shown in FIG. 3, a solid molded body 19 having substantially the same outer shape as the pin holder 5 is formed, and then, as shown in FIG.
9, the inner space 10 and the guide-side pin insertion hole 20 are formed,
Furthermore, as shown in FIG.
A fiber hole forming pin insertion hole 14 that penetrates through and opens to the front end face 12 is formed. The fiber hole forming pin insertion hole 14 and the guide-side pin insertion hole 20 are formed by electrical discharge machining. At this time, since the fiber hole forming pin insertion hole 14 may be formed through the front wall 13, it is possible to easily secure the accuracy of the electric discharge machining as compared with the case where the fiber hole forming pin insertion hole 14 is formed through the formed body 19 in which the internal space 10 is not formed. it can. As a method of forming the internal space 10, various methods such as cutting using a cutting tool such as a micro end mill can be adopted.

Next, as shown in FIG. 6, an inclined surface 11 is formed on the front end surface 12. Next, as shown in FIG.
From the fiber hole forming pin insertion hole 14 of No. 1 to the upper side, that is, a region extending to the upper surface 5b of the holder body 5a (a portion to be a convex portion 15 described later) is left and removed on both sides in a groove shape (FIG.
Groove 11a is formed) to form the convex portion 15 for the guiding groove 24 (see FIG. 9). As a result, the desired pin holder 5 is obtained. The method for forming the pin holder 5 is not limited to the above-described configuration, and can be changed as appropriate. For example, after forming a molded body that is wholly integrated except for the fiber hole molding pin insertion hole 14 and the guide side pin insertion hole 20, the fiber hole molding pin insertion hole 14 and the guide side pin insertion hole 20 are formed in this molded body. May be formed by electrical discharge machining or the like.

The pin holding unit 1, the upper die 2 and the lower die 3
The optical connector ferrule 21 molded by pouring molten resin into the mold 4 using
Optical fiber guiding groove 2 formed by the inclined surface 23 formed by and the convex portion 15 of the inclined surface 11.
4 and the fiber hole forming pin 7 (specifically, the tip small diameter portion 1
7) The optical fiber insertion hole 25 formed by 7) and the guide pin hole 2 formed by the guide pin hole forming pin 8
6 and 6. When the die 4 is clamped, the tip of the fiber hole forming pin 66 is inserted into the hole 72 of the lower die 64, and the tip of the guide pin hole forming pin 67 is inserted into the hole 71 of the lower die 64.

With the pin holding unit 1 configured by inserting the fiber pin hole forming pin 7 and the guide pin hole forming pin 8 into the pin holder 5 as described above, the fiber hole forming pin formed with high precision by electric discharge machining is inserted. Since the outer peripheral surface of the fiber hole forming pin 7 (specifically, the outer peripheral surface of the main portion 16) comes into close contact with the inner surface of the hole 14, does the gap in the fiber hole forming pin insertion hole 14 substantially disappear? , Or very small. Therefore, when the optical connector ferrule 21 is resin-molded by the mold 4 using the pin holding unit 1, the molten resin filled in the mold 4 is effectively inserted into the fiber hole molding pin insertion hole 14. Be prevented. Moreover, since the fiber configuration type pin insertion hole 14 is formed in the pin holder 5 that is an integrally molded product, the molten resin intrudes into the fiber pin hole forming pin insertion hole 14, and the intruded melting occurs. Even if a lateral pressure is applied to the fiber hole forming pin 7 by the resin, the fiber hole forming pin 7 is constrained by the front wall 13 around the fiber hole forming pin insertion hole 14 so as not to be displaced, and the holding accuracy is high. Maintained. However, according to the pin holding unit 1, it is possible to effectively prevent the intrusion of the molten resin into the fiber hole forming pin insertion hole 14 and the displacement (positional deviation) of the fiber hole forming pin 7 due to the intruding molten resin. The holding accuracy of the fiber hole forming pin 7 can be stably maintained for a long period of time. Further, as a result, the maintenance interval such as removal of the resin that has entered the fiber hole molding pin insertion hole 14 is lengthened, and there is an advantage that the labor and cost required for maintenance can be greatly reduced.

In the pin holding unit 1, the inclined surface 23 formed in the optical connector ferrule 21 (FIG. 8, FIG. 8) can be obtained by simply adjusting the shape of the inclined surface 11 formed on the front wall 13 of the pin holder 5. 9)), the inclination angle can be widely supported. Further, by processing the inclined surface 11 (formation of the ridges 15 and the like), it is possible to widely accommodate the shape and size of the guiding groove 24.

Although the optical connector ferrule has been described as an example of the resin-molded optical component in the above embodiment, the present invention is not limited to the optical connector ferrule and may be any optical component having an optical fiber insertion hole. However, any other one may be used. Further, the specific shape of the pin holder is not limited to the above-mentioned embodiment, and can be changed as appropriate. For example,
In the above-described embodiment, the pin holder having the inclined surface 11 on the front end surface 12 is illustrated, but the pin holder according to the invention of claim 1 is not limited to this, and a shape having no inclined surface 11 can also be adopted. Is. The specific shape and dimensions of the mold configured using the pin holding unit according to the present invention can be changed as appropriate.

[0028]

As described above, according to the pin holding unit and the pin holder according to the present invention, the molten resin enters the fiber hole molding pin insertion hole and the displacement of the fiber hole molding pin due to the melted resin penetrates ( Since it is possible to effectively prevent the positional deviation and the like, it is possible to stably maintain the holding accuracy of the fiber hole forming pin for a long period of time. Further, this increases the maintenance interval such as removal of resin that has entered the fiber hole molding pin insertion hole, and thus has the advantage that the labor and cost required for maintenance can be greatly reduced.

In the optical connector ferrule manufactured by forming an inclined surface inclined with respect to the axis of the fiber hole molding pin insertion hole as in the invention of claim 2,
It is possible to obtain the effect of easily forming an inclined surface that facilitates the operation of inserting the optical fiber into the optical fiber insertion hole.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a mold configured by using a pin holding unit according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the pin holder according to the embodiment of the present invention.

FIG. 3 is an example of a method of molding the pin holder according to the embodiment of the present invention.

FIG. 4 is an example of a method of molding the pin holder according to the embodiment of the present invention.

FIG. 5 is an example of a method of molding the pin holder according to the embodiment of the present invention.

FIG. 6 is an example of a method of molding the pin holder according to the embodiment of the present invention.

7A and 7B are diagrams showing a pin holder according to an embodiment of the present invention, in which FIG. 7A is a perspective view and FIG. 7B is a perspective view showing the vicinity of a front end face.

8 is a cross-sectional view showing an optical connector ferrule formed using the mold of FIG.

9 is a cross-sectional view taken along the line LL of FIG. 8 according to the exemplary embodiment of the present invention.

FIG. 10 is a plan view showing an example of an MT type optical connector ferrule.

11 is a side view showing the MT type optical connector ferrule of FIG.

12 is a sectional view showing the MT type optical connector ferrule of FIG. 10, and is a sectional view taken along the line JJ of FIG.

13 is an exploded perspective view showing a metal mold for resin molding of the MT optical connector ferrule of FIG.

FIG. 14 is a side view showing the vicinity of the tip of a pin holding unit (medium size) used in the mold of FIG.

FIG. 15 is a sectional view taken along the line KK of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pin holding unit 4 ... Mold 5 ... Pin holder 7 ... Fiber hole forming pin 11 ... Inclined surface 12 ... Front end surface 13 ... Front wall 14 ... Fiber hole Molding pin insertion hole 21 ... Optical connector ferrule 25 ... Optical fiber insertion hole

Claims (3)

[Claims] 1. When molding an optical component (21) having an optical fiber insertion hole (25), it is attached to a mold (4) and used to form the optical fiber insertion hole. Of the pin holder (5) of the front end face (1
A fiber hole forming pin insertion hole (14) through which the fiber hole forming pin (7) for forming the optical fiber insertion hole is inserted in the front wall (13) forming 2) is opened at the front end face. Pin holder (5) characterized in that 2. The pin holder according to claim 1, wherein an inclined surface (11) that is inclined with respect to an axis of the fiber hole forming pin insertion hole is formed in the front end surface so that the fiber hole forming pin insertion hole opens. Pin holder characterized by being. 3. A pin holding unit for molding an optical component, which is used for forming an optical fiber insertion hole by attaching to a mold when molding an optical component having an optical fiber insertion hole, The pin holder according to claim 1 or 2, and a fiber hole forming pin inserted into the fiber hole forming pin insertion hole of the pin holder so that a tip portion thereof projects from the front end face. Holding unit (1).