JP2009204943A - Sleeve for optical fiber, and core pin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and practical sleeve for optical fiber for holding a pair of optical fibers movably back and forth while the axes of the counter ends of the optical fibers are substantially matched with each other. <P>SOLUTION: The sleeve for the optical fibers holds the counter ends of the pair of optical fibers inserted into a through-hole via a transparent material in a butted state. The through-hole includes a linear optical fiber guide hole 2 for guiding the movement of the counter ends so that its diameter is slightly larger than that of the optical fibers and the axes of the counter ends are substantially matched with each other, tapered optical fiber induction sections 3 connected to both ends of the optical fiber guide hole 2, and an optical fiber induction hole 4 with a diameter larger than that of the optical fiber guide hole 2 connected to the sleeve end side of the optical fiber induction sections 3. The optical fiber guide hole 2 is provided with a slit section 5 that has a length in the axial direction of the through-hole and opens at a width of ≤40% of the circumference of the optical fiber guide hole 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical fiber sleeve and a core pin.

  In the fiber laying work of optical fiber communication using a single mode optical fiber, a fusion splicing of the fiber has been conventionally used. In this method, a large and expensive connecting device is required for each construction site, and a power source is also required for the construction. From these, various mechanical splices have been invented / manufactured by various companies, but the spread of mechanical splice connection instead of fusion bonding has been promoted due to differences in connection performance, poor workability, and high costs. There is no current situation.

  Patent Document 1 represents an existing mechanical splice, in which a pair of fibers are inserted into a groove and the fibers are pressed and positioned by another member. Japanese Patent Application Laid-Open No. 2004-228561 enables a connection with less loss by bringing a pair of fibers having a coaxial degree into contact with each other using an extremely high-precision hole diameter. Further, a manufacturing method of a metallic ferrule is described in Patent Document 3, a sleeve for a mechanical splice with a slit is shown in FIG. 15, and a taper capable of guiding a fiber and a fiber guiding hole are shown in FIG. Patent Document 4 describes an example in which a connector is configured using a similar capillary.

  In fiber connection of optical fiber communication using a single mode fiber, a pair of fibers are inserted into a part having a groove for inserting the fiber as in Patent Document 1, and the position is determined according to the groove accuracy by using a separate member. It is a typical structure of the conventional mechanical splice that holds down. On the other hand, there are some sleeves that do not hold the fiber as in Patent Document 2. However, in this patent document 2, the fiber is bonded and fixed outside the sleeve, and consequently the fiber cannot move with respect to the sleeve. Patent Document 4 uses a spring in the length direction of a pair of fibers to maintain the connection state, and can be expected to reduce the connection change due to temperature change and the mechanical stress on the fiber. Again, the fiber cannot move relative to the sleeve.

  Therefore, in the above configuration, the fiber cannot be moved while being fixed with respect to the sleeve. For example, the fiber cannot be bent when the fiber is bent, which is not preferable.

Japanese Patent No. 2540686 Japanese Patent No. 3955617 Japanese Patent No. 3308266 JP-A-11-160580

  By the way, in order to make the fiber contained in the sleeve slidable (movable forward and backward) in the longitudinal direction of the fiber, a gap is generated at the tip of the fiber generated from a difference in linear expansion coefficient between the quartz glass and at least the material of the sleeve, or to the fiber Therefore, there is a need for a mechanical splice that prevents the coupling efficiency from deteriorating due to the stress generated from the temperature and an inexpensive sleeve used therefor.

  In the case of making it slidable, the V, U, or semicircular groove is not pressed on the opening side, so that it cannot be positioned in all directions. For this reason, a sleeve for guiding a fiber with a round hole having no opening in the longitudinal direction as in Patent Document 2 is used. However, a metal sleeve as in Patent Document 3 is very expensive and is a slidable type. This has hindered the spread of mechanical splices.

  That is, in order to manufacture the metal sleeve as in Patent Document 3, a pipe shape finished in advance with a highly accurate hole diameter in the process of manufacturing a ferrule as described in Patent Document 3 is prepared, and the outer shape and the fiber inlet are formed. It is necessary to perform additional processing by cutting the fiber guiding part that is to be cut, and further, by cutting or grinding the groove used for air venting at the center, and then removing the cutting burr and cleaning it is necessary. In addition to requiring additional machining of inner and outer diameters one by one using a lathe, cutting burrs are difficult to remove, requiring manual work, and it is inevitable that the cost is increased accordingly.

  The present invention has been made in view of the current situation as described above, and without fixing the optical fiber, the optical fiber is placed in a state in which the axes of the opposed ends of the pair of optical fibers are substantially aligned in the optical fiber guide hole. It is an object of the present invention to provide an optical fiber sleeve and a core pin excellent in practicality capable of realizing a structure that can be held back and forth at a very low cost.

  The gist of the present invention will be described with reference to the accompanying drawings.

  There is a through hole into which an optical fiber penetrating from one end side to the other end side can be inserted, and opposing ends of a pair of optical fibers inserted from one end side and the other end side of the through hole are inserted through a transparent material. A resin-made optical fiber sleeve containing a filler to be held in a butted state, wherein the through-hole is slightly larger in diameter than the optical fiber and the axial center of the opposed end portions of the pair of optical fibers is A linear optical fiber guide hole 2 that can guide the opposing end to advance and retreat so as to be substantially coincident with each other, and is continuously provided at both ends of the optical fiber guide hole 2 so as to increase in diameter toward the end of the sleeve. A tapered optical fiber guiding portion 3 for guiding the opposite end portions of the optical fiber to the optical fiber guide hole 2 and the optical fiber connected to at least the sleeve end portion side of the one optical fiber guiding portion 3 Guide hole 2 The optical fiber guide hole 2 has a length in the axial direction of the through hole and opens with a width of 40% or less of the circumference of the optical fiber guide hole 2. In addition, the present invention relates to an optical fiber sleeve characterized in that a slit portion 5 that allows the transparent material to be discharged from between the opposed end portions is provided.

  In addition, a through hole through which an optical fiber penetrating from one end side to the other end side can be inserted, and a transparent material is used for the opposite end portions of the pair of optical fibers inserted from one end side and the other end side of the through hole, respectively. A resin-made optical fiber sleeve containing a filler that is held in a butted state, wherein the through hole has a diameter slightly larger than the diameter of the optical fiber and is an axis of opposed ends of the pair of optical fibers. A straight optical fiber guide hole 2 having a length of 1 mm or more and 5 mm or less that can guide the opposite end to advance and retreat so that the centers substantially coincide with each other, and a sleeve end that is connected to both ends of the optical fiber guide hole 2 respectively. A tapered optical fiber guiding portion 3 that increases the diameter toward the portion side and guides the opposing end portions of the pair of optical fibers to the optical fiber guide hole 2, respectively, and a sleeve end of at least one of the optical fiber guiding portions 3 On the side And an optical fiber guide hole 4 having a diameter of 0.2 mm or more larger than the optical fiber guide hole 2, and the length of the optical fiber guide hole in the axial direction of the through hole. A slit having a shorter length of 0.5 mm or more and less than 4.5 mm and a width of 40% or less of the circumference of the optical fiber guide hole 2 to allow the transparent material to be discharged from between the opposed end portions. By providing the portion 5, the optical fiber can be held forward and backward in a state where the axial centers of the opposed ends of the pair of optical fibers are substantially matched in the optical fiber guide hole 2 without fixing the optical fiber. Thus, the optical fiber guide hole 2 is configured as described above, and this relates to an optical fiber sleeve.

  The optical fiber sleeve according to any one of claims 1 and 2, wherein the slit portion 5 is integrally formed when the optical fiber sleeve is formed.

  4. The optical fiber sleeve according to claim 1, wherein a difference between the diameter of the optical fiber guide hole 2 and the diameter of the optical fiber is set to be less than 1 μm. 5. is there.

  Further, a refractive index matching material having a refractive index equivalent to that of the optical fiber is adopted as the transparent material, and the refractive index matching material is provided in the optical fiber guiding portion 3 and the slit portion 5. Item 5. The optical fiber sleeve according to any one of Items 1 to 4.

  6. The optical fiber according to claim 1, comprising glass beads or a thermoplastic or thermosetting resin to which glass beads and an inorganic filler are added in a weight ratio of 40% or more. This relates to the sleeve.

  7. The optical fiber sleeve according to claim 1, wherein an inclination angle of the optical fiber guiding portion 3 is set to 30 ° or more and 90 ° or less.

  Moreover, it is a core pin used in order to manufacture the optical fiber sleeve of any one of Claims 1-7, Comprising: The optical fiber guide hole which forms the said optical fiber guide hole 2 of the said optical fiber sleeve It consists of divided bodies 6 and 7 that can be divided between the forming portion 12 and the optical fiber guiding portion forming portion 13 that forms the one optical fiber guiding portion 3, and the joining end 8 of one divided body 6 is conical. A core pin characterized in that it is set to a convex part or a hemispherical convex part, and the joint end 9 of the other divided body 7 is set to a receiving concave part that fits into the conical convex part or the hemispherical convex part without a gap. It is related to.

  Since the present invention is configured as described above, the optical fiber is held so as to be able to advance and retract in a state where the axial centers of the opposed ends of the pair of optical fibers are substantially aligned in the optical fiber guide hole without fixing the optical fiber. An optical fiber sleeve and a core pin with excellent practicality capable of realizing the obtained structure at a very low cost.

  Embodiments of the present invention that are considered suitable (how to carry out the invention) will be briefly described with reference to the drawings, illustrating the operation of the present invention.

  Opposing end portions of the optical fibers inserted from one end side and the other end side of the through hole are guided by the optical fiber guiding portion 3 to enter the optical fiber guide hole 2, and the optical fiber guide hole 2 has a substantially axial center. Matched to match.

  At this time, since the transparent material (and the gas generated from the transparent material) provided between the opposite ends of the optical fiber is discharged from the slit portion 5 formed in the optical fiber guide hole 2, the transparent material enters. Without being hindered, the opposed end portions of the pair of optical fibers can be abutted so as to substantially coincide with each other in the optical fiber guide hole 2 via a transparent material (being opposed to each other).

  Further, since the slit portion 5 is opened with a width of 40% or less of the circumference of the optical fiber guide hole 2, the optical fiber is well guided even in the middle portion of the optical fiber guide hole 2 where the slit portion 5 is provided. . That is, if the opening is made with a width of 50% of the circumference, the optical fiber cannot be suppressed on the half side of the optical fiber guide hole 2, and the opposite end of the optical fiber is lifted to the opening side. Axis misalignment occurs. In this respect, according to the present invention, the opening is 40% or less of the circumference of the optical fiber guide hole, and the suppression portion of the optical fiber remains on the opening side, so that such a problem does not occur.

  Furthermore, since it is a resin sleeve containing a filler, it is difficult to produce scratches from the optical fiber, and it can be manufactured very simply by injection molding or the like, and the cost is reduced accordingly.

  Therefore, the present invention is made of resin and has a simple structure, as well as being able to guide the advance and retreat well over the entire length of the optical fiber guide hole by preventing the rising of the opposite end of the optical fiber without having to suppress the optical fiber. It is possible to provide a sleeve that is excellent in mass productivity and that can hold the optical fiber in a freely movable manner while preventing axial misalignment.

  A specific embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, this embodiment has a through hole into which an optical fiber penetrating from one end side to the other end side can be inserted, and a pair of holes inserted respectively from one end side and the other end side of the through hole. A resin-made optical fiber sleeve 1 containing a filler that holds a facing end of an optical fiber in a butted state through a transparent material, wherein the through hole is slightly larger in diameter than the optical fiber. A linear optical fiber guide hole 2 having a length of 1 mm or more and 5 mm or less capable of guiding the opposing ends forward and backward so that the axial centers of the opposing ends of the pair of optical fibers substantially coincide with each other, and the optical fiber guide holes A tapered optical fiber guiding portion 3 continuously provided at both ends of the sleeve 2 and having a diameter increasing toward the end of the sleeve to guide the opposing ends of the pair of optical fibers to the optical fiber guide holes 2, respectively. Said one optical fiber An optical fiber guide hole 4 having a diameter of 0.2 mm or more larger than the optical fiber guide hole 2 continuously provided on the sleeve end portion side of the guide portion 3, The transparent material is discharged from between the opposing ends by opening in the axial direction of the hole with a length of 0.5 mm or more and less than 4.5 mm and a width of 40% or less of the circumference of the optical fiber guide hole 2. The permissible slit portion 5 is provided so that the optical fiber can be advanced and retracted in a state where the axial centers of the opposed ends of the pair of optical fibers are substantially aligned in the optical fiber guide hole 2 without fixing the optical fiber. This optical fiber guide hole 2 is configured so that it can be held.

  This embodiment incorporates the technology of resin ferrules used in multi-fiber ferrules and has been realized by numerous devices. A pair of single-mode optical fibers are butted together at the approximate center of the optical fiber guide hole 2 to reduce the number of axes. It is used for the purpose of close contact (via a transparent material) with a shift (axial misalignment).

  Each part will be specifically described.

  As shown in FIG. 1, the sleeve 1 is provided with an optical fiber guide hole 2 in which the opposite ends of the optical fiber are abutted, and both ends of the optical fiber guide hole 2, and the optical fiber is smoothly passed from both sides. A configuration having an optical fiber guiding portion 3 composed of a chamfered portion or an R portion for insertion, and an optical fiber guiding hole 4 continuously provided on the outer end side (sleeve end portion side) of the optical fiber guiding portion 3 It is. In the figure, reference numerals 15 and 16 denote corner portions which are connection points between the optical fiber guide hole 2 and the optical fiber guiding portion 3.

  This sleeve 1 is made of glass beads or glass beads so that powder does not come out or get caught by scratching when inserting the cleaved glass fiber tip, and so as to ensure a highly accurate hole size over a certain length. And an inorganic filler added at a weight ratio of 40% or more, is formed of a thermosetting or thermoplastic resin.

  Specifically, the sleeve is made of a single-mode optical fiber made of quartz glass. Even if a broken edge of an optical fiber such as a single mode is inserted, it is necessary that the sleeve enters smoothly and does not generate scratch powder. In addition, the shrinkage in the molding process is large and the hole accuracy cannot be secured. In addition, the glass fiber reinforced resin that is generally available is caught. The liquid crystal polymer also feels like a catch. In order to solve these problems, in this embodiment, polyphenylene sulfide (hereinafter referred to as PPS), in which glass beads having no edges of about several μm to 10 μm are kneaded at a weight ratio of 40% or more and less than 70% by weight that can be injection-molded. ) Or a thermosetting resin such as an epoxy resin. In addition, it is considered possible to use a resin in which small particles or small flat inorganic fillers are put together with glass beads as a substitute for glass beads. In this embodiment, the glass beads are made of PPS with 60% by weight. It should be noted that such a combination of fine particles and a hard and brittle resin facilitates removal processing such as cutting when burrs appear in the corner portion 15 described later.

  By the way, in optical fiber communication using a single mode optical fiber, the outer diameter of the single mode optical fiber is 125 μm and the core diameter is about 10 μm. In a mechanical splice that requires an axial displacement of a pair of optical fibers using the sleeve hole position accuracy using a sleeve position accuracy of 1 μm or less, the guide hole that guides the fiber is a uniform gap of about 1 μm from the fiber outer diameter. Accurate hole accuracy is required.

  It is the optical fiber guide hole 2 that guides the outer diameter of the optical fiber (guides the forward and backward movement of the optical fiber) so that the axes of the pair of optical fibers coincide with each other at a substantially central portion. The axial displacement of the pair of optical fibers is reduced by setting the diameter to a large extent.

  The optical fiber guide hole 2 is set to have a length of 1 mm or more and 5 mm or less so as to absorb the fiber position error and the deflection error of both optical fibers inserted from one end side and the other end side. Specifically, in making the optical fiber guide hole 2 without bending, it is effective to shorten the optical fiber guide hole length a, but at least 1 mm from the workability using a mechanical splice, as a practical range 2-3 mm is considered necessary. On the other hand, the longer the optical fiber guide hole length a is, the more stable it is, and there are merits such as an increased work margin in the fiber cladding stripping work, etc., but the mold parts are easily bent and the entire product is long. Therefore, a range of 1 mm to 5 mm is desirable. In actual implementation, feasibility has been confirmed at 2 to 3 mm, and in this embodiment, it is set to about 3 mm.

  Further, when one optical fiber is inserted from one end side of the through hole into the substantially central portion in the longitudinal direction of the optical fiber guide hole 2, the other optical fiber is inserted into the optical fiber guide hole 2 from the other end side. The slit portion 5 is provided for discharging the gas or liquid (transparent material) to the outside of the sleeve. The slit portion 5 is integrally formed when the sleeve 1 is formed. Therefore, it is not necessary to use a special process or the like for providing the slit portion 5, and it can be provided at a very low cost.

  Specifically, when an optical fiber on the side to be inserted later is inserted in a substantially central portion of the optical fiber guide hole 2 from 0.5 mm to 4.5 mm shorter than the optical fiber guide hole length a, The slit part 5 which does not spoil the guide of an optical fiber is provided by allowing discharge | emission of a liquid. The slit length b is set to 0.5 mm or more and 4.5 mm or less, which is shorter than the fiber guide hole length a of 1 mm or more and 5 mm or less because the molding process is difficult unless the slit length is shorter than the fiber guide hole. In this embodiment, it is set to about 2 mm. In the drawing, reference numeral 10 denotes a communication recess that is recessed in the outer peripheral surface of the sleeve 1 and communicates the slit portion 5 with the outside.

  That is, an optical fiber called matching oil or the like is generally used between the opposing ends of the optical fiber (substantially the central position in the longitudinal direction of the optical fiber guide hole 2) to fill the unevenness of the fiber tip and improve optical coupling. A refractive index matching liquid (transparent material, silicon oil in the present embodiment) having the same refractive index as that in FIG. The volume required to fill the unevenness of the opposite end of the optical fiber is about several pl (picoliter), but this opposite end is used so that the opposite end (opposite end face) of the optical fiber is surely filled. A few nl (nanoliter) is applied in advance, and many portions enter between the optical fiber guide hole 2 and the optical fiber and between the opposite ends of the optical fiber, and the excess is discharged from the slit portion 5. Therefore, if the slit portion 5 is not provided, the gap between the optical fiber and the optical fiber guide hole 2 is so small that it is difficult for the liquid to pass therethrough. This causes a problem that the other optical fiber to be inserted later does not enter the desired position. become.

  Further, as shown in FIG. 3, the width of the slit portion 5 is configured to be 40% or less of the circumference of the optical fiber guide hole 2. This is because the optical fiber guide hole is formed so that the axial center of the optical fiber does not shift even in the portion where the slit portion 5 is formed, that is, the optical fiber can be guided forward and backward substantially uniformly over the entire length of the optical fiber guide hole 2. The upper half of 2 is kept as much as possible. Therefore, the presence of the slit portion 5 does not allow the opposite end portion of the optical fiber to be lifted. The lift of the opposite end portion of the optical fiber is caused by the upper half portion of the optical fiber guide hole 2 forming the slit portion 5. It is suppressed by the curved surface portion 18, and it becomes possible to guide the advance and retreat uniformly so that the axial center does not shift over the entire length of the optical fiber guide hole 2.

  The optical fiber guiding portion 3 provided between the optical fiber guide hole 2 and the optical fiber guiding hole 4 has an inclination angle c of 30 ° or more and 90 ° or less in order to smoothly insert the optical fiber into the optical fiber guide hole 2. It has a tapered surface. The tapered surface of the optical fiber guiding portion 3 may be linear in cross section as shown in FIG. 1, or as shown in FIG. 4, the optical fiber guiding portion 3, the optical fiber guide hole 2, and the optical fiber guiding hole. 4 may be curved in a cross-sectional view connecting with a curve (that is, it may be a curved taper approximating a linear taper of 30 ° or more and 90 ° or less). When the inclination angle (guidance angle) of the optical fiber guiding portion 3 increases, the optical fiber tends to scratch the resin, but if it is 90 ° or less, it can be smoothly inserted. It is necessary to set the angle between 30 ° and 90 ° only on one side where the connecting end portions 8 and 9 of the core pin split bodies 6 and 7 are present, and the other side is set at 30 ° and 90 °. There is no need to do this, and a left-right asymmetric shape may be used.

  By the way, when an optical fiber is inserted into the sleeve 1, a sense of resistance is produced by the optical fiber guiding portion 3, and when this is passed, smoothness starts. Although the fiber guiding portion 3 is provided with the above-mentioned inclination angle to take measures against scraping, there is room for improvement from the viewpoint of workability. On the other hand, the fiber is cut by a fiber cutter and connects the fibers cut to each other to compensate for the optical defect of causing reflection when a difference in refractive index occurs by filling the gap generated from the flatness, inclination, and surface roughness of the tip. As described above, a refractive index matching material is put in advance at the opposite end portion of the fiber, or after application and filling, the slit portion 5 is filled. In this embodiment, a refractive index matching material mainly using silicon oil is applied in advance to the optical fiber guiding part 3 in addition to the slit part 5 where the opposite ends of the optical fiber are abutted with each other. Therefore, the insertion property of the fiber is improved. In other words, the first optical fiber inserted first has a refractive index matching material applied to the optical fiber guiding portion 3 to reduce the sliding resistance and smoothly enters the optical fiber guiding portion. 3, while the excess refractive index matching material coated and filled in the optical fiber guide hole 2 is discharged out of the slit from the slit portion 5, the opposite end portion of the optical fiber is not uneven on the opposite end surface of the optical fiber. It is configured such that it can be completely adhered in a state flattened by a refractive index matching material.

  Further, optical fiber guide holes 4 each having a diameter of 0.2 mm or more are provided on the outer side (fiber end side) of the optical fiber guide part 3 provided on both sides of the optical fiber guide hole 2. This is because when injection molding is performed using a core pin, an injection molding gate 11 (provided in an injection molding die) is positioned at the outer peripheral position of the optical fiber guide hole 4, so that the injection pressure is an optical fiber guide hole of the core pin. This is to prevent the forming part 12 from being directly applied.

  That is, the optical fiber guide hole 4 is an unnecessary part as a product function, but the optical fiber guide hole diameter d plays an important function in partial processing, and the optical fiber is injected when resin is injected from the gate. In order not to break the mold for forming the guide hole 2, that is, to prevent the optical fiber guide hole 2 from being bent greatly, the optical fiber guide hole diameter d, which is a portion that receives the injection pressure, is set larger than the optical fiber guide hole 2. Yes. The optical fiber guide hole diameter d needs to be 0.2 mm or more. Furthermore, when molding. While slowing the injection speed, the resin is devised so that the resin flows in the hole direction in the vicinity of the optical fiber guide hole 2 so that a bending load is not applied to the mold part forming the optical fiber guide hole 2. Although there is no problem in strength when the diameter d of the optical fiber guide hole is increased, the upper limit is about 0.6 mm due to the size of the entire product and the dimensional relation of the periphery. In actual implementation, feasibility has been confirmed with a diameter of 0.25 mm to 0.35 mm, and in this embodiment, the diameter is set to 0.3 mm.

  The outer diameter 125 μm of the optical fiber to be abutted in the present embodiment is about the same as the outer diameter dimension of the thick hair, and the core pin prepared for aligning this position is also an ultra-fine pin making full use of advanced processing technology, Furthermore, the surface of the tip is embodied by ultra-fine processing. Also in the molding process, the injection speed is reduced so as not to bend or buckle the core pin.

  As this core pin, a split body that can be divided between an optical fiber guide hole forming portion 12 that forms the optical fiber guide hole 2 of the optical fiber sleeve and an optical fiber guide portion forming portion 13 that forms the optical fiber guide portion 3. 6. The joint end 8 of the one divided body 6 is set to a conical convex portion or a hemispherical convex portion, and the joint end portion 9 of the other divided body 7 is the conical convex portion or the hemisphere. What is set in the receiving concave portion that fits with the convex portion without gap is adopted. In the figure, reference numeral 14 denotes an optical fiber guide hole forming portion for forming the optical fiber guide hole 4.

  Specifically, the core pin is divided at the corner portion 15 (A portion in FIG. 5). 6 and 7 show the cross-sectional shapes of the connecting end portions of the core pin split bodies 6 and 7. In a configuration in which the core pin is divided at the corner portion 15, if the axes of the optical fiber guide hole 2 and the optical fiber guiding portion 3 are misaligned, a burr is generated at the corner portion 15 and the optical fiber cannot be inserted. In the worst case, scratching burr creates a fatal problem that enters between the optical fibers to be matched and causes a large coupling loss. In order to solve this, as shown in FIGS. 6 and 7, the joint ends 8 and 9 of the divided bodies 6 and 7 constituting the core pin are configured to be concavo-convexly fitted. FIG. 6 shows an example in which the joining end 8 of one divided body 6 is a conical convex portion, and the joining end 9 of the other divided body 7 is a receiving concave portion that fits substantially congruently with this conical convex portion. 7 is an example in which the joining end portion 8 of one divided body 6 is a hemispherical convex portion, and the joining end portion 9 of the other divided body 7 is a receiving concave portion that substantially fits with this hemispherical convex portion. In the present embodiment, the joint end 8 of one divided body 6 is a conical convex portion, and the joint end 9 of the other divided body 7 is a receiving concave portion that receives this conical convex portion.

  At the core pin split butted portion, the split body having the concave edge portion, such as the core pin tip cone receiving recess and the core pin tip hemisphere receiving recess, is easily damaged, and the guiding angle of the optical fiber guiding portion 3 is 30 ° or more. Less than 90 ° is also significant. That is, when the angle is less than 30 °, the divided body is easily damaged. In this embodiment, it is set to 60 °. In addition, since it is also possible to form this by connecting the curves according to the angle, in this case, it is regarded as an approximate curve of the angle. In addition, the corner portions 15 and 16 can be asymmetrical, and one side is, for example, 25 ° and the other side is 60 °. However, it is important that the angle on the mold dividing side is 30 ° or more and 90 ° or less. . And you may use the method of once forming in this range, and finishing a corner part by additional machining, such as cutting.

  In addition, a common side gate or submarine gate is used as the gate, and multiple pins such as 4 or 8 can be obtained in a single molding cycle by placing a protruding pin on the protruding pin mark 17 in FIG. As a result, it was possible to realize a component that is so inexpensive that it cannot be compared with a metal sleeve.

  The present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate. For example, the fiber can be easily applied not only to a single fiber (a pair) but also to a sleeve of 4 fibers (four pairs) or eight fibers (eight pairs). It can also be used for holey fibers that have recently been spotlighted as having a small bending radius. Further, the present invention is not limited to a single mode fiber, and can be applied to a multimode fiber having a fiber core size of 50 μm or the like.

It is a schematic explanatory sectional drawing of a present Example. It is a schematic explanatory front view of a present Example. It is an expansion outline explanatory sectional view of the important section of this example. It is an expansion schematic explanatory sectional drawing of the principal part of another example. It is a schematic explanatory side view of the core pin used for manufacture of a present Example. It is a schematic explanatory sectional drawing of the connection end part of the division body which comprises a core pin. It is a schematic explanatory sectional drawing of the connection end part of the division body which comprises a core pin. It is general | schematic explanatory sectional drawing of another example.

Explanation of symbols

2 Optical fiber guide hole 3 Optical fiber guiding part 4 Optical fiber guiding hole 5 Slit part 6/7 Divided body 8-9 Joint end
12 Optical fiber guide hole forming part
13 Optical fiber guiding part forming part

Claims (8)

  There is a through hole into which an optical fiber penetrating from one end side to the other end side can be inserted, and opposing ends of a pair of optical fibers inserted from one end side and the other end side of the through hole are inserted through a transparent material. A resin-made optical fiber sleeve containing a filler to be held in a butted state, wherein the through-hole is slightly larger in diameter than the optical fiber and the axial center of the opposed end portions of the pair of optical fibers is A linear optical fiber guide hole capable of guiding the opposite end to advance and retreat so as to substantially coincide with each other, and the pair of optical fibers which are continuously provided at both ends of the optical fiber guide hole and are expanded toward the sleeve end side. A tapered optical fiber guiding portion for guiding the opposite end portions of the optical fiber to the optical fiber guide hole, and a diameter larger than that of the optical fiber guide hole continuously provided on the sleeve end side of at least one of the optical fiber guiding portions. Light The optical fiber guide hole has a length in the axial direction of the through hole and opens with a width of 40% or less of the circumference of the optical fiber guide hole. An optical fiber sleeve, comprising a slit portion that allows the transparent material to be discharged from the optical fiber.   There is a through hole into which an optical fiber penetrating from one end side to the other end side can be inserted, and opposing ends of a pair of optical fibers inserted from one end side and the other end side of the through hole are inserted through a transparent material. A resin-made optical fiber sleeve containing a filler to be held in a butted state, wherein the through-hole is slightly larger in diameter than the optical fiber and the axial center of the opposed end portions of the pair of optical fibers is A straight optical fiber guide hole having a length of 1 mm or more and 5 mm or less that can guide the opposite end to advance and retreat so as to be substantially coincident with each other, and is connected to both ends of the optical fiber guide hole. A tapered optical fiber guiding portion that guides the opposite end portions of the pair of optical fibers to the optical fiber guide holes, and is connected to at least the sleeve end portion of the one optical fiber guiding portion. The light 3. An optical fiber guide hole having a diameter of 0.2 mm or more larger than the eva guide hole, and 0.5 mm or more shorter than the optical fiber guide hole length in the axial direction of the through hole. A slit portion having a length of less than 5 mm and a width of 40% or less of the circumference of the optical fiber guide hole is provided to allow the transparent material to be discharged from between the opposed end portions. The optical fiber guide hole is configured such that the optical fiber can be held forward and backward in a state where the axial centers of the opposed ends of the pair of optical fibers are substantially coincided with each other in the optical fiber guide hole without being fixed. An optical fiber sleeve characterized by.   The optical fiber sleeve according to any one of claims 1 and 2, wherein the slit portion is integrally formed when the optical fiber sleeve is formed.   4. The optical fiber sleeve according to claim 1, wherein a difference between the diameter of the optical fiber guide hole and the diameter of the optical fiber is set to be less than 1 μm. 5.   5. A refractive index matching material having a refractive index equivalent to that of the optical fiber is employed as the transparent material, and the refractive index matching material is provided in the optical fiber guiding portion and the slit portion. The optical fiber sleeve according to any one of the above.   The optical fiber sleeve according to any one of claims 1 to 5, comprising glass beads or a thermoplastic or thermosetting resin to which glass beads and an inorganic filler are added in a weight ratio of 40% or more.   The optical fiber sleeve according to any one of claims 1 to 6, wherein an inclination angle of the optical fiber guiding portion is set to 30 ° or more and 90 ° or less.   It is a core pin used in order to manufacture the optical fiber sleeve of any one of Claims 1-7, Comprising: The optical fiber guide hole formation part which forms the said optical fiber guide hole of the said optical fiber sleeve, It consists of a split body that can be split between the one optical fiber guide part and the optical fiber guide part forming part, and the joining end of one split body is set to a conical convex part or a hemispherical convex part, The core pin according to claim 1, wherein a joining end portion of the other divided body is set to a receiving concave portion that fits with the conical convex portion or the hemispherical convex portion without a gap.

Images