JP2005041134A - Fiber hole forming pin, mold device for optical connector, and optical connector ferrule - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber hole forming pin which can mold an optical connector ferrule corresponding to small-diameter optical fibers and a mold device for an optical connector. <P>SOLUTION: The fiber hole forming pin 14 has a fiber hole forming part 17 and an auxiliary part 18 which is set on the base end side of the fiber hole forming part 17 and has a diameter larger than that of the fiber hole forming part 17. The joint between the fiber hole forming part 17 and the auxiliary part 18 constitutes a taper part 20. The fiber hole forming part 17 is a pin part forming the fiber hole of the optical connector ferrule. The diameter A of the fiber hole forming part 17 is 50-100 μm. The fiber hole forming pin 14 is formed from a metallic material at least 92 HRA in hardness and at least 570 Gpa in Young's modulus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fiber hole forming pin used for forming a fiber hole of an optical connector ferrule, an optical connector mold apparatus provided with the fiber hole forming pin, and an optical connector ferrule.

As a conventional fiber hole forming pin, there is a pin having a small diameter part for forming a fiber hole of an optical connector ferrule and a large diameter part held on the mold side (see, for example, Patent Document 1).
Japanese Patent Publication No. 2949775

  In recent years, attempts have been made to reduce the mode field diameter (MFD) of the optical fiber and reduce the diameter of the optical fiber itself in order to cope with the small-diameter bending of the optical fiber. However, when trying to reduce the diameter of the optical fiber, it is necessary to reduce the diameter of the fiber hole forming pin for forming the fiber hole of the optical connector ferrule, so that the strength of the fiber hole forming pin does not decrease. I do not get. Therefore, when an optical connector ferrule is molded by molding using a mold apparatus equipped with such a fiber hole forming pin, the fiber hole forming pin is damaged by resin pressure, and consequently cannot be molded. there is a possibility.

  An object of the present invention is to provide a fiber hole forming pin capable of forming an optical connector ferrule corresponding to a small-diameter optical fiber, an optical connector mold apparatus, and an optical connector ferrule compatible with a small-diameter optical fiber. It is.

  The present invention relates to a fiber hole forming pin for forming a fiber hole in a fiber hole forming pin constituting a part of an optical connector mold device for forming an optical connector ferrule having a fiber hole into which an optical fiber is inserted. And an auxiliary portion having a diameter larger than that of the fiber hole forming portion, the diameter of the fiber hole forming portion being 50 to 100 μm, and the fiber hole forming portion and the auxiliary portion. The part is characterized by being integrally formed of a metal material having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more.

  The present invention optimizes the material of the fiber hole forming pin through repeated experiments and evaluations so as to ensure a desired pin strength even when the fiber hole forming pin is reduced in diameter. That is, even when the diameter of the fiber hole forming portion is 50 to 100 μm by using a metal material having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more as the material of the fiber hole forming portion and the auxiliary portion, it is desirable. The pin strength can be obtained. Therefore, the fiber hole forming pin can be prevented from being damaged by the resin pressure when the optical connector ferrule having the small diameter fiber hole is molded. As a result, it is possible to mold an optical connector ferrule corresponding to the small-diameter optical fiber.

  Preferably, the connection portion between the fiber hole forming portion and the auxiliary portion has a tapered shape, and the taper angle of the connection portion is 45 degrees or less. In this case, since the stress concentrated on the base of the fiber hole forming portion is reduced when the optical connector ferrule is formed, the fiber hole forming pin can be more reliably prevented from being damaged.

  Preferably, the surface roughness of the fiber hole forming portion is 0.03 μm or less. In this case, since the frictional force generated when the fiber hole forming pin is pulled out from the mold is reduced, it is possible to more reliably prevent the fiber hole forming pin from being damaged.

  Further, preferably, in the fiber hole forming portion, an effective length for forming the fiber hole is 0.3 to 2 mm. In this case, since the bending of the fiber hole forming pin is suppressed, the fiber hole forming pin is not easily damaged, and the influence on the polishing of the ferrule end face can be reduced.

  Further, the present invention provides an optical connector mold apparatus for molding an optical connector ferrule having a fiber hole into which an optical fiber is inserted, with a core including the above-described fiber hole forming pin, and a core interposed therebetween, An upper mold and a lower mold for forming a cavity corresponding to the optical connector ferrule are provided.

  Thus, as described above, even when the diameter of the fiber hole forming portion of the fiber hole forming pin is reduced, a desired pin strength can be obtained. Can be prevented from being damaged. Accordingly, it is possible to mold an optical connector ferrule corresponding to the small-diameter optical fiber.

  Preferably, the upper die or the lower die is provided with a supporting projection having a through hole that penetrates the auxiliary portion of the fiber hole forming pin. As a result, when the optical connector ferrule is molded, the auxiliary portion is supported by the supporting projection, and thus bending of the fiber hole forming portion is suppressed. As a result, the bending of the fiber hole of the optical connector ferrule can be reduced.

  The optical connector ferrule of the present invention includes a fiber hole into which an optical fiber is inserted, and a fiber insertion auxiliary hole formed so as to be connected to the fiber hole and having a diameter larger than that of the fiber hole. The diameter is 50 to 100 μm. Thereby, it is possible to form an optical connector having a small-diameter optical fiber that can cope with small-diameter bending.

  Preferably, the optical connector ferrule is formed by the above-described optical connector mold apparatus. Thereby, a high-quality optical connector ferrule having a good fiber hole shape can be obtained.

  According to the present invention, the diameter of the fiber hole forming portion of the fiber hole forming pin is 50 to 100 μm, and the fiber hole forming portion and the auxiliary portion are integrally formed of a metal material having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more. Therefore, an optical connector ferrule having a fiber hole corresponding to a small-diameter optical fiber can be formed without damaging the fiber hole forming pin.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a fiber hole forming pin, an optical connector mold device, and an optical connector ferrule according to the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing an embodiment of an optical connector mold apparatus according to the present invention. In the figure, an optical connector mold apparatus 1 of the present embodiment forms an MT type optical connector ferrule. An example of the MT type optical connector ferrule is shown in FIGS.

  The optical connector ferrule 2 is provided between a pair of guide holes 3 into which guide pins (not shown) are inserted, and between these guide holes 3, and a plurality (here, optical fibers) (not shown) are inserted. 4) fiber holes 4. The diameter (diameter) of the optical fiber inserted into each fiber hole 4 is 50 to 100 μm, and the diameter of the fiber hole 4 is also about 50 to 100 μm. Moreover, the arrangement pitch of each fiber hole 4 is 125-250 micrometers.

  On the rear side of each fiber hole 4 in the optical connector ferrule 2, a plurality of fiber insertion auxiliary holes 5 having a diameter larger than that of the fiber hole 4 are formed so as to be connected to each fiber hole 4 through the taper portion 6. The fiber insertion auxiliary hole 5 is formed to facilitate the insertion of the optical fiber into the fiber hole 4 from the rear side of the optical connector ferrule 2. The diameter of the fiber insertion auxiliary hole 5 is, for example, about 200 μm when the pitch is 250 μm.

  A plurality of fiber grooves 7 are formed on the rear side of each fiber insertion auxiliary hole 5 in the optical connector ferrule 2 so as to be connected to each fiber insertion auxiliary hole 5. The fiber groove 7 serves as a guide when an optical fiber is inserted into the fiber hole 4 from the rear side of the optical connector ferrule 2.

  A window hole 8 for injecting adhesive is formed in the upper surface of the optical connector ferrule 2, and the optical fiber inserted into each fiber hole 4 is fixed by injecting the adhesive from the window hole 8. To do.

  Returning to FIG. 1, the optical connector mold apparatus 1 includes a core 9 and a lower mold 11 that forms a cavity 10 (see FIG. 5) corresponding to the optical connector ferrule 2 with the core 9 interposed therebetween. And an upper mold 12.

  The core 9 is composed of a pair of guide hole forming pins 13, a plurality (four in this case) of fiber hole forming pins 14, and a pair of clamping members that clamp the proximal end portion of each guide hole forming pin 13. 15a and 15b, and a pair of clamping members 16a and 16b that project from one end face of each of the clamping members 15a and 15b and clamp the proximal end portion of each fiber hole forming pin 14.

  The guide hole forming pin 13 is a pin that forms the guide hole 3 of the optical connector ferrule 2. Each fiber hole forming pin 14 is disposed between a pair of guide hole forming pins 13. The arrangement pitch of each fiber hole forming pin 14 is 125 to 250 μm.

  As shown in FIG. 4, the fiber hole forming pin 14 includes a fiber hole forming portion 17 and an auxiliary portion 18 provided on the proximal end side of the fiber hole forming portion 17 and having a larger diameter than the fiber hole forming portion 17. And a fixed portion 19 having a substantially rectangular parallelepiped shape provided on the base end side of the auxiliary portion 18. A connecting portion between the fiber hole forming portion 17 and the auxiliary portion 18 constitutes a tapered portion 20.

  The fiber hole forming portion 17 is a pin portion that forms the fiber hole 4 of the optical connector ferrule 2. The diameter (diameter) A of the fiber hole forming portion 17 is 50 to 100 μm like the optical fiber inserted into the fiber hole 4. The auxiliary portion 18 is a pin portion that forms the fiber insertion auxiliary hole 5 of the optical connector ferrule 2. The diameter (diameter) B of the fiber insertion auxiliary hole 5 is, for example, about 200 μm.

  Such a fiber hole forming pin 14 is formed of a metal material having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more. As the metal material, for example, a cemented carbide containing iron, cobalt, or carbon is used. By comprising in this way, the intensity | strength with respect to a shaping | molding process comes to be ensured, even when the diameter of the fiber hole formation part 17 is as small as 50-100 micrometers.

  In order to further increase the strength of the fiber hole forming portion 17 with respect to the molding process, the taper angle θ of the tapered portion 20 is preferably 45 degrees or less, and the surface roughness of the fiber hole forming portion 17 is 0.03 μm. The following is preferable. In addition, the surface roughness here is centerline average roughness (Ra) prescribed | regulated by JIS etc.

  In the fiber hole forming portion 17, the effective length (corresponding to the length D of the fiber hole 4 shown in FIG. 3) for forming the fiber hole 4 of the optical connector ferrule 2 is preferably 0.3 to 2 mm. is there. Thereby, since the bending of the fiber hole forming pin 14 is suppressed, the fiber hole forming pin 14 is hardly bent or damaged. Further, there is almost no influence on the polishing of the ferrule end face performed after the optical connector ferrule 2 is formed.

  Returning to FIG. 1, the holding members 16 a and 16 b have a hole portion (not shown) into which the fixing portion 19 of the fiber hole forming pin 14 is fitted and a base end side portion of the auxiliary portion 18 of the fiber hole forming pin 14. A groove 21 to be inserted is provided. Thereby, the fiber hole forming pin 14 can be firmly held by the clamping members 16a and 16b.

  A pair of V grooves 22 for positioning each guide hole forming pin 13 sandwiched between the sandwiching members 15a and 15b is provided at both ends of the lower mold 11 one by one. The upper mold 12 is provided with a pair of rectangular grooves 23 for pressing the guide hole forming pins 13 inserted into the V grooves 22. In addition, a plurality of V grooves 24 for positioning the fiber hole forming portions 17 of the respective optical fiber hole forming pins 14 are provided at one end portion of the lower mold 11, A space 25 for arranging the holding members 16a and 16b is provided.

  On the inner wall surface of the lower mold 11, support protrusions 26 are provided so as to form the window holes 8 of the optical connector ferrule 2 and support the fiber hole forming pins 14. The support protrusion 26 is provided with a plurality of through holes 27 that allow the auxiliary portions 18 of the fiber hole forming pins 14 to pass therethrough. The supporting protrusion 26 is provided with a plurality of U grooves 28 into which the fiber hole forming pins 14 penetrating the through holes 27 are inserted so as to be connected to the through holes 27. Thereby, the fiber hole forming portion 17 of each fiber hole forming pin 14 is accurately aligned.

  When the optical connector ferrule 2 is molded using the optical connector mold apparatus 1 configured as described above, each guide hole forming pin 13 is disposed in the V groove 22 as shown in FIG. The fiber hole forming pin 14 is passed through the through hole 27 of the supporting projection 26 to place the fiber hole forming part 17 in the V groove 24, and in this state, the upper mold 11 and the lower mold 12 are closed. Then, a molten resin is filled into the cavity 10 formed by the upper mold 11, the lower mold 12 and the core 9. As the molten resin, PPS (polyphenylene sulfide) resin, epoxy resin, or the like is used. Then, after the resin in the cavity 10 is solidified, each guide hole forming pin 13 and each fiber hole forming pin 14 are pulled out from the cavity 10. Then, the upper mold 11 and the lower mold 12 are opened. Thereby, the optical connector ferrule 2 as shown in FIG. 2 is formed.

  In such a molding process, since the fiber hole forming pin 14 is formed of a high-strength metal material as described above, the fiber hole forming pin 14 is caused by stress when the molten resin flows or the resin hardens. There is almost no damage. Thereby, it can prevent that the optical connector ferrule 2 cannot be shape | molded. Further, since the taper angle θ of the tapered portion 20 of the fiber hole forming pin 14 is set to 45 degrees or less, the stress applied to the base of the fiber hole forming portion 17 of the fiber hole forming pin 14 is reduced. 14 can be more effectively prevented.

  Further, since the fiber hole forming pin 14 is supported by the supporting protrusions 26 of the lower mold 11 at the time of molding, the fiber hole forming portion 17 of the fiber hole forming pin 14 is caused by the stress when the molten resin flows. There is almost no bending with respect to the auxiliary portion 18.

  Further, by smoothing the surface roughness of the fiber hole forming portion 17 of the fiber hole forming pin 14 to 0.03 μm or less, the frictional force generated when the fiber hole forming pin 14 is pulled out is reduced, and the fiber hole forming portion 17 Stress applied to the root is reduced. For this reason, the fiber hole forming portion 17 is hardly damaged by the pulling force of the fiber hole forming pin 14.

  Therefore, even if the fiber hole forming portion 17 of the fiber hole forming pin 14 is made small in order to correspond to the small diameter optical fiber, the high quality optical connector ferrule 2 with almost no deformation or bending of the fiber hole 4 is obtained. Can be obtained.

  Here, a fiber hole forming pin was formed with a metal material (hard metal containing iron, cobalt, carbon) having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more, and the MT connector ferrule was actually formed. When the diameter of the hole forming portion is 50 to 100 μm, it was confirmed that the fiber hole forming pin can be molded with almost no damage.

  For example, the bending fracture strength of a general fiber hole forming pin (a pin made of a cemented carbide having a hardness of 90.6 to 91.8 HRA, a Young's modulus of 540 to 550 Gpa, and a fiber hole forming portion having a diameter of 125 μm) Is 1 and the bending fracture strength of the fiber hole forming pin formed of the same metal material and having a fiber hole forming portion diameter of 80 μm is about 0.17. In this case, it was difficult to mold the MT connector ferrule.

  On the other hand, when a fiber hole forming pin having a fiber hole forming portion diameter of 80 μm is formed of a cemented carbide having a hardness of 93.5 HRA and a Young's modulus of 570 Gpa, the bending fracture strength of the fiber hole forming pin is generally It was 0.5 to 0.7 with respect to a typical fiber hole forming pin, which was greatly improved. In this case, the MT connector ferrule could be formed.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, an MT type multi-core connector ferrule is formed. However, the present invention is not limited to this, and an MPO / MPX / MT-RJ type multi-core connector ferrule, a single-core connector ferrule, etc. It can also be applied to the molding of

  Further, in the optical connector mold apparatus of the above embodiment, the supporting protrusion 26 having the through hole 27 for forming the window hole 8 of the optical connector ferrule 2 and penetrating the fiber hole forming pin 14 is provided. The present invention can also be applied to a case in which a protrusion that does not have such a through hole and merely forms a window hole of an optical connector ferrule is provided on the lower mold or the upper mold.

It is a disassembled perspective view which shows one Embodiment of the metal mold | die apparatus for optical connectors which concerns on this invention. It is a perspective view which shows an example of the optical connector ferrule shape | molded using the metal mold | die apparatus for optical connectors shown in FIG. FIG. 3 is a vertical sectional view of the optical connector ferrule shown in FIG. 2. It is a side view of the fiber hole formation pin shown in FIG. FIG. 2 is a vertical sectional view of the optical connector mold apparatus shown in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mold apparatus for optical connectors, 2 ... Optical connector ferrule, 4 ... Fiber hole, 9 ... Core, 10 ... Cavity, 11 ... Lower mold, 12 ... Upper mold, 14 ... Fiber hole formation pin, 17 ... Fiber hole forming part, 18 ... auxiliary part, 20 ... taper part (connection part), 26 ... supporting projection part, 27 ... through hole.

Claims (8)

In a fiber hole forming pin constituting a part of an optical connector mold apparatus for molding an optical connector ferrule having a fiber hole into which an optical fiber is inserted,
A fiber hole forming portion for forming the fiber hole, and an auxiliary portion provided on a proximal end side of the fiber hole forming portion and having a larger diameter than the fiber hole forming portion;
The fiber hole forming portion has a diameter of 50 to 100 μm,
The fiber hole forming pin, wherein the fiber hole forming part and the auxiliary part are integrally formed of a metal material having a hardness of 92 HRA or more and a Young's modulus of 570 Gpa or more. 2. The fiber hole forming pin according to claim 1, wherein a connecting portion between the fiber hole forming portion and the auxiliary portion has a tapered shape, and a taper angle of the connecting portion is 45 degrees or less. The fiber hole forming pin according to claim 1 or 2, wherein the surface roughness of the fiber hole forming portion is 0.03 µm or less. The fiber hole forming pin according to claim 1, wherein an effective length for forming the fiber hole is 0.3 to 2 mm in the fiber hole forming portion. In an optical connector mold apparatus for molding an optical connector ferrule having a fiber hole into which an optical fiber is inserted,
A core including the fiber hole forming pin according to any one of claims 1 to 4,
An optical connector mold apparatus comprising: an upper mold and a lower mold that form a cavity corresponding to the optical connector ferrule with the core interposed therebetween. 6. The optical connector according to claim 5, wherein the upper die or the lower die is provided with a supporting projection having a through hole that penetrates the auxiliary portion of the fiber hole forming pin. Mold equipment. A fiber hole into which the optical fiber is inserted;
A fiber insertion auxiliary hole formed so as to be connected to the fiber hole and having a diameter larger than the fiber hole;
An optical connector ferrule, wherein the fiber hole has a diameter of 50 to 100 μm. The optical connector ferrule according to claim 7, wherein the optical connector ferrule is molded by the optical connector mold apparatus according to claim 5.

Images