JP2004333569A - Optical fiber-incorporated plastic ferrule, metallic mold therefor and method of manufacturing the ferrule - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a precise plastic ferrule in which no eccentricity of an optical fiber exists and to provide a method to produce the ferrule using a simple process. <P>SOLUTION: The ferrule is provided with: a pair of metallic molds 2 and 3 in which a ferrule main body molding cavity section 9 and a protrusion forming cavity section 10 are communicated with each other and the molds 2 and 3 are divided into two parts along the axis direction at the section 10; at least two gates 12 which are opened at the opposing positions of the section 10; and optical fiber holding recessed sections 13 and 14 which are formed at the tip parts of the section 9 in the metallic molds 2 and 3 and to which both tip sections of an optical fiber 30 are inserted. Since plastic material 20 is integrally inserted and molded with the optical fiber 30, no eccentricity exists and the production process is simplified. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ferrule made of plastic containing optical fiber, a mold for molding the same, and a method of manufacturing a ferrule made of plastic containing optical fiber.
[0002]
[Prior art]
The ferrule is incorporated into an optical connector for connecting the optical fibers so as to concentrically abut the ends of the optical fibers facing each other. As the ferrule, those made of ceramics zirconia, metal or plastic are used.
[0003]
FIGS. 8 and 9 show a ferrule 100 made of ceramic zirconia or metal. A ferrule body 120 is attached to an outer peripheral surface of a ferrule body 110 extending in an axial direction. The ferrule body 110 is formed by inserting the small-diameter second ferrule portion 112 coaxially from one end side (right end side) of the large-diameter first ferrule portion 111.
[0004]
The collar portion 120 is attached to the outer peripheral surface of the ferrule main body 110 so as to protrude in the radial direction, and is formed into a shape corresponding to the inside of the optical connector in order to prevent rotation and removal of the ferrule main body 110. You. Fiber holes 111a and 112a are formed in the first ferrule part 111 and the second ferrule part 112 so as to communicate in the axial direction, and the optical fiber 130 is inserted into the fiber holes 111a and 112a in the communicating state. Accordingly, the optical fiber 130 penetrates through the fiber main body 0.
[0005]
In such a structure, a ferrule made of ceramic zirconia is expensive in material itself, and requires many steps for molding, assembling parts, and polishing, and also requires an outer diameter of the ferrule and an optical fiber. However, there is a problem that the workability is poor because the dimensions such as the inner diameter of the optical fiber vary and the optical fiber needs to be inserted into a fine fiber hole after molding.
[0006]
Metal ferrules are less expensive than ceramic zirconia, but require molding and polishing as well as ceramic zirconia ferrules, and require insertion of optical fibers into fiber holes.
[0007]
Plastic ferrules have attracted attention in recent years because of their advantages in that they are inexpensive in material and can be mass-produced, and they are also highly accurate and lightweight. The production of this plastic ferrule is performed by injecting a molten plastic material into a mold.
[0008]
In the production of conventional plastic ferrules, a metal pipe was placed in a cavity with a mold pin inserted into one end of the metal pipe, and the molten plastic was integrated with the metal pipe by injecting molten plastic into the cavity. Insert molding is performed, and after removing this molded product from a mold, an optical fiber is inserted into a metal pipe (for example, see Patent Document 1).
[0009]
[Patent Document 1]
JP-A-2000-162470 (pages 4 to 5, FIGS. 1 and 4)
[0010]
[Problems to be solved by the invention]
However, in the production of a conventional plastic ferrule, it is necessary to insert an optical fiber into a molded product formed by a mold. However, since the diameter of the optical fiber is small, the workability of insertion is poor. . In addition, there is a problem that the yield is poor because the optical fiber is broken at the time of insertion.
[0011]
The present invention has been made in consideration of such a conventional problem, and eliminates the work of inserting an optical fiber, thereby improving workability and improving the yield. It is an object of the present invention to provide a plastic ferrule containing an optical fiber inserted without the same, a mold for molding the same, and a method of manufacturing a plastic ferrule containing an optical fiber.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a plastic ferrule containing an optical fiber according to the first aspect of the present invention is a plastic ferrule containing an optical fiber having a flange projecting from an outer peripheral surface of a ferrule main body, wherein a plastic material is integrally formed with the optical fiber. It is characterized by being formed by insert molding.
[0013]
According to the first aspect of the present invention, since the optical fiber and the plastic ferrule are integrally formed, it is not necessary to insert the optical fiber into the ferrule later, so that the workability is improved, and the optical fiber breakage due to the insertion is prevented. And the yield is improved.
[0014]
In addition, in the case where the optical fiber is inserted later, since it is necessary to separately fill the adhesive, there is a problem that the optical fiber is eccentrically inserted and held, but the present invention does not cause the optical fiber to be misaligned. It is.
[0015]
The mold for molding a plastic ferrule containing an optical fiber according to the invention of claim 2 is a mold for molding a plastic ferrule having a flange protruding from an outer peripheral surface of a ferrule main body, wherein the ferrule main body molding cavity is formed. And a pair of dies which are communicated with each other and are divided in the axial direction by the flange forming cavity, and at least two gates which are opened at positions opposed to the flange forming cavity. And an optical fiber holding recess formed at the end of the ferrule body molding cavity in each mold and into which both ends of the optical fiber are inserted.
[0016]
According to the second aspect of the invention, the optical fiber is held in the cavity by inserting both ends of the optical fiber into the optical fiber holding recesses of the pair of molds, and in this holding state, the molten plastic material is poured from the gate into the cavity of the mold. Injected into, then cooled and cured. Thereby, the ferrule in a state where the optical fiber penetrates in the axial direction can be formed.
[0017]
In such an invention, since the ferrule is formed in a state where the optical fiber is inserted into the mold, it is not necessary to insert the optical fiber into the ferrule later, and the workability is improved, and the light caused by the insertion is improved. There is no fiber breakage, and the yield is improved.
[0018]
Further, since the gate is opened at a position facing the cavity for molding the flange, the injected plastic material can be uniformly filled in the cavity of the mold. Therefore, a ferrule having a good shape can be formed.
[0019]
According to a third aspect of the present invention, there is provided a mold for molding a plastic ferrule containing an optical fiber according to the first aspect, wherein a tapered guide recess is continuously provided around the optical fiber holding recess. Features.
[0020]
According to the third aspect of the present invention, by inserting the end of the optical fiber into the tapered guide recess, the end of the fiber can be guided to the optical fiber holding recess. Therefore, the optical fiber can be easily and accurately inserted into the mold.
[0021]
A method of manufacturing a plastic ferrule containing an optical fiber according to the invention of claim 4 is a method of manufacturing a plastic ferrule having a flange portion protruding from an outer peripheral surface of a ferrule main body using a molding die. Both ends of the optical fiber are inserted and held in the optical fiber holding recesses of a pair of molds having a cavity portion and a flange portion forming cavity portion, and in this holding state, a plastic material is placed from a position facing the flange portion forming cavity portion. Is injected.
[0022]
According to the invention of claim 4, the optical fiber can be inserted into the mold by inserting both ends of the optical fiber into the optical fiber holding recess of the mold. In this state, the molten plastic material is injected into the mold. Thus, a ferrule in a state where the optical fiber penetrates in the axial direction can be manufactured.
[0023]
Therefore, since it is not necessary to insert the optical fiber into the ferrule after the ferrule is formed, the workability is improved and the yield is improved. Further, since the molten plastic material is injected from a position facing the cavity for molding a flange, a ferrule having a good shape can be molded.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.
[0025]
FIG. 1 is a cross-sectional view of a molding die of this embodiment, FIG. 2 is a plan view showing an arrangement of a gate, FIG. 3 is a perspective view showing an arrangement of a gate with respect to a molded product, and FIG. FIG. 5 is a perspective view of a plastic ferrule containing an optical fiber, and FIG. 6 is a perspective view of a tip portion thereof.
[0026]
As shown in FIG. 1, a molding die 1 is arranged so that a pair of dies 2 and 3 face each other. The dies 2 and 3 are opposed to each other by being attached to the mold mounting plates 4 and 5, respectively. One of the dies 2 is on the fixed side and the other dies 3 is on the movable side. A sprue 6 penetrates through the mold 2 on the fixed side in the thickness direction, and a runner 7 communicating with the sprue 3 is formed laterally on the other mold 3 on the operating side. In these molds 2 and 3, a plastic ferrule 21 is molded by injecting a molten plastic material 20 in a direction indicated by an arrow in a clamped state, and then the mold is opened. With this mold opening, the plastic ferrule 21 is taken out.
[0027]
A cavity 8 for molding a plastic ferrule 21 is formed in the pair of dies 2 and 3. The cavity 8 communicates with the ferrule main body forming cavity 9 for forming the ferrule main body 22 in the ferrule 21 and the flange forming cavity 10 for forming the flange 23 protruding from the ferrule main body 22. It is constituted by that.
[0028]
The ferrule body molding cavity 9 is formed to extend in the axial direction over the pair of dies 2 and 3. The flange forming cavity 10 is formed in a pair of molds 2 and 3 so as to radially expand from the cavity 9 in a state of communication with the ferrule body forming cavity 9 communicating therewith. In this embodiment, as shown in FIG. 5, the flange portion 23 of the ferrule 21 has three steps of a large-diameter first flange portion 23a, a small-diameter flange portion 23c, and an intermediate-diameter intermediate flange portion 23b located therebetween. The flange forming cavity 10 is formed in three steps corresponding to these.
[0029]
A gate 12 is opened in the cavity 8 composed of the ferrule main body forming cavity 9 and the flange forming cavity 10. The gate 12 injects the molten plastic material 20 from the runner 7 into the cavity 8, and is opened to correspond to the flange forming cavity 10. In this case, the gate 12 is opened so as to correspond to the cavity portion 10a for forming the large-diameter first flange portion 23a in the flange forming cavity portion 10.
[0030]
As shown in FIGS. 2 and 3, the gates 12 are opened such that four gates 12 face the cavity portion 10 a of the flange portion forming cavity portion 10. That is, the four gates 12 are formed in a mold so as to be at 90-degree intervals on the circumference, and face the gates 12 facing in a straight line. As described above, the four gates 12 are opened at positions facing the cavity 10a in the flange forming cavity 10, so that the flow of the molten plastic material 20 injected from the facing gates 12 as shown in FIG. After colliding in the cavity portion 10, the molten plastic material 20 diffuses into the cavity 8, so that the cavity 8 can be uniformly filled with the molten plastic material 20. Thereby, the ferrule 21 having a good shape can be formed.
[0031]
In this embodiment, each gate 12 is formed by cutting only the upper surface of the other mold 3, and the upper portions are covered by the lower surfaces of the pair of molds 2 by clamping. It becomes a gate structure. In such a gate structure, a process of penetrating the mold 2 is not required, so that the mold can be easily formed.
[0032]
Further, in this embodiment, the optical fiber holding concave portions 13 and 14 are formed in the molds 2 and 3. These optical fiber holding concave portions 13 and 14 are formed at axial ends of the ferrule main body forming cavity portion 9 in the respective dies 2 and 3. In one mold 2, an optical fiber holding recess 13 is formed by cutting the end of the ferrule body molding cavity 9 along the axial direction, and in the other mold 3, the ferrule body molding cavity 9 is formed. The optical fiber holding recess 14 is formed by cutting the end of the cavity 9 along the axial direction. These optical fiber holding recesses 13 and 14 are for inserting the ends of the optical fiber 30. By this insertion, the optical fiber 30 is held in the molds 2 and 3 along the axial direction. Can be.
[0033]
Guide recesses 15 and 16 are provided continuously with the respective optical fiber holding recesses 13 and 14. The guide recess 15 is connected to the optical fiber holding recess 13 on one mold 2 side, and the guide recess 16 is connected to the optical fiber holding recess 14 on the other mold 3. These guide recesses 15 and 16 have the largest diameter on the starting end side of the optical fiber holding recesses 13 and 14 and gradually become smaller in the longitudinal direction of the optical fiber holding recesses 13 and 14 (tapered taper). ). By forming the guide recesses 15 and 16 having such a shape, when the ends of the optical fiber 30 are inserted into the optical fiber holding recesses 13 and 14, the ends of the optical fiber 30 are smoothly placed. Since it is guided to 13 and 14, the optical fiber 30 can be inserted easily and with high precision.
[0034]
When the ferrule 21 is molded by using the above molding die, the optical fiber 30 is inserted into the cavity 8 by inserting both ends of the optical fiber 30 into the concave portions 13 and 14 for holding the optical fiber. I do. In this state, the molten plastic material 20 is injected into the cavity 8 from the four gates 12 via the sprue 6 and the runner 7. After the injection of the plastic material 20, the molds 2 and 3 are cooled and the ferrule 21 is molded by hardening the plastic material 20. Thereafter, the ferrule 21 is taken out of the molds 2 and 3 by opening the mold.
[0035]
FIGS. 4 and 5 show the molded ferrule 21, and a flange portion 23 integrally protrudes from the outer peripheral surface of the ferrule main body 22. The ferrule main body 22 is formed by extending a large-diameter first ferrule portion 22a and a small-diameter second ferrule portion 22b in the axial direction, and an optical fiber 30 penetrates the inside thereof. Both ends of the optical fiber 30 inserted into the optical fiber holding recesses 13 and 14 project from the ferrule main body 22.
[0036]
In these moldings, the optical fiber 30 is held in the cavity 8 by inserting both ends thereof into the optical fiber holding recesses 13 and 14, and the molten plastic material 20 is injected in this state to perform molding. The ferrule 21 in which the fiber 30 penetrates in the axial direction can be manufactured. For this reason, it is not necessary to insert the optical fiber into the ferrule later, and the workability is dramatically improved. Further, the yield is improved because the optical fiber is not broken due to the insertion.
[0037]
For the ferrule 21 taken out of the mold, the end face is polished according to the purpose such as flat polishing, pre-dome polishing, and oblique polishing. That is, as shown in FIG. 6, since the projections 27 are formed at the portions corresponding to the guide recesses 15 and 16 of the mold, the projections 27 are polished to have a good conical shape or the like.
[0038]
FIG. 7 shows another shape of ferrule 31 that can be manufactured according to the present invention. The ferrule 31 includes a ferrule main body 34 including a first ferrule part 32 and a second ferrule part 33 having the same diameter, and a flange part 35 projecting radially from the outer peripheral surface of the ferrule main body 34. The flange part 35 is the largest. It is formed by a first flange portion 35a having a small diameter and a second flange portion 35b having a small diameter. In the ferrule 31, the same molding as described above can be performed by providing the gate at the corresponding position in the first flange portion 35a.
[0039]
The present invention is not limited to the above embodiments, and various modifications can be made. For example, at least two gates for injecting the resin may be used as long as they are opened at positions facing the cavity for molding the flange.
[0040]
【The invention's effect】
As described above, according to the plastic ferrule of the present invention, since the optical fiber and the plastic ferrule are integrally formed, it is not necessary to insert the optical fiber into the ferrule later, and the workability is improved. At the same time, the yield is improved. Further, since the optical fiber is not eccentrically inserted and held in the center of the plastic ferrule, a precise plastic ferrule free from axial misalignment can be obtained.
[0041]
Further, according to the molding die of the present invention, since the ferrule is molded in a state where the optical fiber is inserted into the die, it is not necessary to insert the optical fiber into the ferrule later, and the workability is improved. At the same time, the yield is improved. Since the plastic material can be uniformly filled in the cavity of the mold, a ferrule having a good shape can be molded.
[0042]
Furthermore, according to the manufacturing method of the present invention, it is possible to manufacture the ferrule in a state where the optical fiber penetrates in the axial direction, so that it is not necessary to insert the optical fiber into the ferrule later, thereby improving workability and improving the yield. Is improved. Further, the optical fiber is not eccentrically inserted and held in the center of the plastic ferrule.
[Brief description of the drawings]
FIG. 1 is a sectional view of a molding die according to an embodiment of the present invention.
FIG. 2 is a plan view showing an arrangement of a gate with respect to a cavity.
FIG. 3 is a perspective view showing an arrangement of a gate with respect to a ferrule to be molded.
FIG. 4 is a perspective view showing a cross section of a ferrule in which an optical fiber is insert-molded.
FIG. 5 is a perspective view of a ferrule in which an optical fiber is insert-molded.
FIG. 6 is a perspective view showing an end face of a ferrule in which an optical fiber is insert-molded.
FIG. 7 is a perspective view of another shaped ferrule to be molded.
FIG. 8 is a perspective view of a ferrule made of ceramic zirconia or metal.
FIG. 9 is a perspective view showing a cross section of a ferrule made of ceramic zirconia or metal.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 Molding mold 2, 3 Mold 8 Cavity 9 Cavity part for molding ferrule body 10 Cavity part 12 for forming flange part 13, 14 Optical fiber holding recess 15, 16 Guide recess 20 Plastic material 21, 31 Ferrule 22, 34 Ferrule main body 23, 35 Collar 30 Optical fiber

Claims (4)

What is claimed is: 1. A plastic ferrule containing an optical fiber, wherein a flange portion protrudes from an outer peripheral surface of a ferrule body, wherein the plastic material is insert-molded with a plastic material integrally with the optical fiber. A molding die for molding a plastic ferrule containing an optical fiber with a flange protruding from the outer peripheral surface of the ferrule body,
The ferrule body molding cavity and the flange molding cavity communicate with each other, and the pair of molds divided in the axial direction by the flange molding cavity are opened at positions opposed to the flange molding cavity. Characterized in that it comprises at least two gates formed and an optical fiber holding recess formed at the end of the ferrule body molding cavity in each mold and into which both ends of the optical fiber are inserted. Mold for molding plastic ferrule with fiber. 2. The mold for molding a plastic ferrule containing an optical fiber according to claim 1, wherein a tapered guide concave portion is continuously provided around the optical fiber holding concave portion. A method for manufacturing a plastic ferrule containing an optical fiber having a flange portion protruding from the outer peripheral surface of the ferrule body using a molding die,
The two ends of the optical fiber are inserted and held in the optical fiber holding recesses of a pair of molds having a ferrule main body forming cavity and a flange forming cavity, and in this holding state, the flange forming cavity opposes. A method for manufacturing a plastic ferrule containing an optical fiber, comprising injecting a plastic material from a position.

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