JP4094907B2 - Multi-fiber optical connector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is related to connectors for multi-core optical fiber.
[0002]
[Prior art]
As a driving force for rapid progress in the information and communication field in recent years and the spread of FTTH (Fiber To The Home), the use of optical fiber cables that facilitate large-capacity transmission is being promoted. As a result, demand for multi-fiber optical connectors for connecting a plurality of optical fibers tends to increase. The multi-fiber optical connector is not only connected by using a multi-core (two-core, four-core, eight-core, twelve-core, etc.) optical fiber bundled together, but also a tape core There is also a demand for a structure in which multiple cores are connected in a multistage manner.
[0003]
In an optical fiber connector, a part called a ferrule that supports an optical fiber inserted into insertion holes arranged at a predetermined pitch is used. Since the optical fiber has a thin outer diameter (125 μm), workability when inserting into the insertion hole is extremely poor, and if the insertion hole is difficult to see, the optical fiber may be broken during insertion. Therefore, conventionally, a structure has been proposed in which a guide groove protruding before the insertion hole is provided to improve workability during insertion. However, the structure in which the guide groove is provided has no problem when only one stage of the tape core wire is connected, but has a problem that its manufacture is extremely difficult when the stage is connected in multiple stages.
[0004]
As a multi-fiber optical connector in which tape core wires are stacked in multiple stages as described above, for example, Japanese Patent Application Laid-Open No. 2001-66463 discloses a structure in which a semicircular guide groove is provided in the inner space of a ferrule. The guide groove of this publication is an improvement of the structure of the guide groove disclosed in Japanese Patent Application Laid-Open No. 11-84177, so that the guide groove can be manufactured even if the density of the optical fiber is increased. The diameter of the groove is made smaller than the pitch of the vertical arrangement and the horizontal arrangement of the optical fibers. That is, the size of the guide groove is defined to be small so that a mold for making the guide groove can be manufactured even if the arrangement pitch of the optical fibers is reduced by increasing the density. Then, in consideration of workability when the guide grooves are provided in multiple stages, the lower guide groove is protruded longer stepwise than the upper guide groove.
[0005]
[Problems to be solved by the invention]
As shown in the publication, the shape and size of the guide groove of Japanese Patent Laid-Open No. 2001-66463 is defined by the gap between the molding pins positioned by the spacer. Therefore, the shape of the protruding guide groove increases in the horizontal direction when the number of insertion holes in the horizontal direction is increased, and decreases in the vertical thickness when the pitch of the vertical arrangement is reduced. At the end of molding, a long and thin guide groove must be taken out by drawing the mold. If the optical fiber density is increased, the thickness of the guide groove becomes several μm to several tens of μm. Therefore, even if the dimensions can be secured in the drawing, it is difficult to pull out the optical connector without damage in practice. It was a big problem at the time of manufacture.
[0006]
Furthermore, when the lower guide groove is protruded long and provided in multiple stages, the lower protrusion dimension becomes longer as the number of stages increases, and the guide groove is thin in the vertical direction and long in the horizontal direction. It becomes longer in the depth direction. Therefore, it becomes more difficult to form the guide groove of the optical connector without breakage when it is formed in multiple stages, and it is a very big problem to manufacture the structure with high density by providing the protruding guide groove with high yield. .
[0007]
Such problems in mind, the present invention is an object of the present invention to provide a multiple-core optical connector insertion of an optical fiber that has excellent easy workability.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the multi-fiber optical connector of the present invention employs the following means.
[0009]
That is, in claim 1, while the inner space of the ferrule for receiving an optical fiber, Ru insertion surface with insertion holes of the optical fiber of the plurality of columns are formed to be inclined to the arrangement direction of the rows, the inner space and the outside In the multi-fiber optical connector in which the opening is formed at a position where the insertion hole can be visually recognized, the insertion hole is formed between the insertion holes based on the cut angle of the insertion hole formed according to the inclination of the insertion surface. The remaining cut-out angle of the insertion surface is formed to be large .
[0010]
In this means, when the optical fiber inserted into the ferrule is inserted into the insertion hole, the insertion operation is performed while the insertion hole on the insertion surface inclined from the opening is visually recognized.
In addition, by cutting out the angle of insertion face remainder between the insertion holes each other than the angle of the cut-out of the insertion hole is formed so as to be larger, when viewed insertion hole from the opening, the interval between the insertion hole rows It spreads out and it becomes easy to distinguish the insertion holes of different rows.
[0011]
According to a second aspect of the present invention, in the multi-fiber optical connector according to the first aspect, the inclination of the insertion surface is formed so as to protrude from a position close to the opening to a position far from the opening.
[0012]
With this means, when the insertion hole is faced from the opening, the insertion surface protrudes further away from the opening, so that all of the insertion holes arranged in a row can be visually recognized. Then, when inserting the optical fiber, if the insertion work is performed in order from the row of the insertion holes far from the opening, it is possible to work while visually checking the insertion holes regardless of the number of rows.
[0013]
Further, according to claim 3, in the multi-fiber optical connector according to claim 1 or 2, when the insertion hole faces the opening, at least a part of the circumference of the insertion hole is visually recognized as an optical fiber insertion guide. Features.
[0014]
With this means, since the insertion surface in which the insertion hole is formed is cut out obliquely by the inclination, a part of the circumference of the insertion hole appears to protrude from the opening, and the insertion of the optical fiber is seen. It can be used as a guide during work.
[0015]
According to a fourth aspect of the present invention, in the multi-fiber optical connector according to any one of the first to third aspects, the insertion hole includes a small-diameter portion for supporting the inserted optical fiber, and a small-diameter portion located on the insertion surface side. And a large-diameter portion having a larger inner diameter.
[0016]
In this means, since the inner diameter of the large-diameter portion on the insertion surface side is larger than that of the small-diameter portion, the ease of inserting the optical fiber is improved.
[0017]
According to a fifth aspect of the present invention, in the multi-fiber optical connector according to any one of the first to fourth aspects, the opening is also used as an addition port for an adhesive added to fix the optical fiber. And
[0018]
According to this means, when an adhesive is used to fix the optical fiber inserted into the insertion hole, the optical fiber is inserted through the opening after being visually recognized from the outside. The optical fiber is fixed by pouring an adhesive into the inside.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a cross-sectional view of a reference example of a multi- fiber optical connector, FIG. 2 is an external view of a reference example of the multi- fiber optical connector, FIG. 3 is an explanatory diagram showing an optical fiber insertion operation in the multi- fiber optical connector, and FIG. Sectional drawing of the insertion surface of Embodiment (1), FIG. 5 is sectional drawing of the metal mold | die used for manufacturing the multi-fiber optical connector of Embodiment (1).
[0023]
In the multi- fiber optical connector 1, an insertion surface 5 having insertion holes 4 for a plurality of rows of optical fibers 9 is formed inside the ferrule 2 that receives the optical fibers 9 so as to be inclined in the row arrangement direction. The opening 6 that communicates the inside and the outside 24 of the ferrule 2 is formed at a position where the insertion hole 4 can be seen from the outside 24.
[0024]
The ferrule 2 is configured so that the optical fiber 9 can be connected in multiple stages by applying the shape of a positioning pin coupling type MT connector (JIS C5981). The optical fiber 9 is used as a tape core 91 in which a plurality of optical fibers 9 are bundled in a tape shape. The outer coating layer of the tape core 91 is removed at a predetermined end length to expose the optical fiber 9, and the ferrule 2 It is inserted inside and supported at a defined pitch for connection. The ferrule 2 is a substantially rectangular parallelepiped having a stepped portion on the outside, and a receiving port 21 for receiving the tape core wire 91 in the ferrule 2 is provided on one end face side of the ferrule 2 at a position facing the receiving port 21. A support portion 3 that supports the optical fiber 9 is provided on the end face side. An internal space 23 is formed between the support portion 3 and the receiving port 21. A guide hole 22 for a positioning pin is provided outside the support portion 3.
[0025]
The support part 3 has a connection surface 7 on the outside and an insertion surface 5 on the side facing the internal space 23. An insertion hole 4 for inserting the optical fiber 9 is provided so as to penetrate the support portion 3. The insertion holes 4 are arranged in a row to form the insertion hole row 40, and the number of holes in this row is determined by the number of optical fibers 9 included in one tape core 91. The number of columns is determined by the number of tape cores 91 to be connected. In this embodiment (1), since 12 core tapes 91 are stacked in five stages and inserted into the support portion 3, the insertion holes 4 are inserted in 12 rows in a row. The hole row 40 is formed in five rows vertically. Here, the side where the slope of the insertion surface 5 protrudes is the bottom, and the side where the insertion surface 5 is retracted is the top. In FIG. 1, the insertion hole row 40 is arranged with the upper and lower sides of the tapered insertion surface 5 spreading from the top to the bottom as the alignment direction.
[0026]
The opening 6 is formed on one end surface of the ferrule 2 so as to communicate the internal space 23 and the outside 24, but the position is such that the insertion surface 5 can be seen over the insertion surface 5 as shown in FIG. It is opened in a rectangle. That is, it is provided at the position of the ferrule 2 so that the inclination of the insertion surface 5 is projected so as to be farther from the opening 6, and the entire insertion hole 4 can be seen from the opening 6. The opening 6 is also used as an addition port for pouring an adhesive when the optical fiber 9 is fixed after being inserted into the support 3. Since the addition port is a part that is originally provided in an optical connector that is fixed by bonding, it is not necessary to newly provide the opening 6 when it is also used. Note that the shape of the opening 6 is arbitrary as long as the insertion hole 4 can be seen, and may be formed in a U-shape opened to the receiving port 21 side. Further, the position of the opening 6 may be provided at an arbitrary position of the ferrule 2 as long as the insertion hole 4 can be seen, and may be, for example, obliquely above instead of vertically above the insertion surface 5. Furthermore, you may provide the opening part 6 separately from the addition port of an adhesive agent.
[0027]
The insertion hole 4 is a hole that penetrates from the insertion surface 5 to the connection surface 7 of the support portion 3 and is formed in parallel with adjacent holes. And the inclination of the insertion surface 5 is provided so as to be cut out obliquely with respect to the parallel insertion holes 4. In this embodiment (1), since the insertion hole 4 has a circular cross section, the insertion hole 4 exposed on the insertion surface 5 can be seen as an ellipse when facing the opening 6. If the insertion hole 4 is cut vertically without being cut obliquely, the insertion hole 4 cannot be seen even when facing the opening 6, but by tilting the insertion surface 5, Of these, the lower periphery 41 protrudes from the upper periphery 42 and is visible from the opening 6. Accordingly, the lower circumference 41 can be used as a guide when the optical fiber 9 is inserted. Although this lower periphery 41 is a part of the insertion surface 5 and does not protrude from the insertion surface 5, it appears to protrude naturally along the slope as the insertion hole 4 is located on the lower side.
[0028]
As shown in FIG. 1, the amount of protrusion of the lower circumference 41 from the upper circumference 42 is d, and the lower circumference of the lower insertion hole row 40 is lower than the upper circumference 42 of the uppermost insertion hole row 40. If the depth up to 41 is D, these depend on the angle of inclination of the insertion surface 5 (θ in FIG. 1). As the angle θ is smaller, d is larger and the ellipse is swollen and looks larger, and as the angle θ is smaller, D is larger and the entire insertion hole 4 is easier to look around. Therefore, as the angle θ is smaller, the workability of inserting the optical fiber 9 is improved. However, since the difficulty in manufacturing the mold is increased (described later), the value is determined in consideration of both situations. . Specifically, in the case of placing the vertical in five rows of the insertion hole rows 40 to full ferrule 2, the angle θ is preferably in the range of 40 to 80 degrees, more preferably in the range of 60 to 70 degrees.
[0029]
Further, the insertion hole 4 has an inner diameter formed stepwise, and includes a large diameter portion 45, a tapered portion 46, and a small diameter portion 47. The small-diameter portion 47 is provided on the connection surface 7 side. When the optical fiber 9 having an outer diameter of 125 μm is attached, the small-diameter portion 47 is formed to have an inner diameter slightly larger than the outer diameter of the optical fiber 9, for example, a tolerance of about 1 μm. The large diameter portion 45 is provided on the insertion surface 5 side, and has an inner diameter larger than the inner diameter of the small diameter portion 47 so that the optical fiber 9 can be easily inserted into the insertion surface 5. The taper portion 46 has a taper shape provided so as to gradually shift from the large diameter portion 45 to the small diameter portion 47. The pitch within the row of the insertion holes 4 is defined by the tape core 91 of the optical fiber 9 to be used. When the optical fiber 9 has a tape core 91 with a pitch of 250 μm, the pitch in the row of the insertion holes 4 is also 250 μm. Therefore, the inner diameter of the large diameter portion 45 is arbitrarily determined within a range in which the insertion holes 4 adjacent in one row do not interfere with each other. For example, in the case of the optical fiber 9 having an outer diameter of 125 μm and an adjacent pitch of 250 μm in the row, the large diameter portion 45 is formed with an inner diameter of less than 250 μm.
[0030]
The pitch between the rows of the insertion hole rows 40 is also arbitrarily determined within a range in which the insertion holes 4 adjacent to each other in the row direction do not interfere with each other as required for higher density. In the present invention, no guide grooves or shelves are projected between the insertion hole rows 40 arranged vertically as in the prior art Japanese Patent Laid-Open Nos. 2001-66463 and 11-84177. There is no need to secure the dimensions for forming the shelves. Accordingly, the interval between the rows can be reduced and the insertion holes 4 can be brought close to each other in the row direction, so that the density of the optical fibers 9 can be easily increased.
[0031]
The operation of inserting the optical fiber 9 of the multi- fiber optical connector 1 configured as described above will be described with reference to FIG. FIG. 3 shows a state in which the insertion surface 5 is viewed from the opening 6. First, the 12 core optical fibers 91 are removed from the outer coating layer having a predetermined terminal length, and 12 optical fibers 9 are exposed. Then, the optical fiber 9 is inserted into the inner space 23 of the ferrule 2 together with the tape core 91 from the receiving port 21. When the operator faces the insertion surface 5 from the opening 6, all the insertion holes 4 can be seen. Then, using the lower circumference 41 of the insertion hole row 40 positioned at the bottom of the insertion surface 5 as a guide, twelve optical fibers 9 are inserted into the corresponding twelve insertion holes 4 as shown in FIG. , Inserted to a predetermined depth.
[0032]
Subsequently, the optical fiber 9 of the tape core 91 from which the outer coating layer having a predetermined terminal length has been removed is inserted into the internal space 23 from the receiving port 21. At this time, when the insertion surface 5 faces the opening 6, the insertion holes 4 other than the insertion hole row 40 positioned at the bottom can be seen. Then, twelve optical fibers 9 are inserted into the corresponding twelve insertion holes 4 using the lower circumference 41 of the insertion hole row 40 located second from the bottom as a guide. By repeating the same operation, the optical fibers 9 can be sequentially inserted from the lower side to the upper side of the insertion hole row 40, and the 12 cores 91 can be stacked and supported by the support unit 3. Then, an adhesive is poured from the opening 6 to fix the optical fiber 9.
[0033]
Thus, when inserting the optical fiber 9, the operator can always see the insertion hole 4 from the opening 6, so that the operator can work while visually confirming the position of the insertion hole 4. Moreover, since the lower periphery 41 of the insertion hole 4 can be used as a guide, insertion workability can be improved without providing a guide groove or the like.
[0034]
By the way, although the inclination of the insertion surface 5 is made constant in FIG. 1, it is preferable that the insertion surface 5 is inclined as a whole as shown in FIG. an inclined with different angles of insertion surface 5 other than pores (referred to as remaining part 51). That, .theta.1 the angle of cut of the insertion hole 4, and the angle .theta.2 balance 51, .theta.1> .theta.2 to. In this state, when the insertion hole 4 is viewed from the opening 6, the interval between the insertion hole rows 40 is widened, and the insertion holes 4 in different rows can be easily distinguished. This angle, the inner diameter of the pitch and the large-diameter portion 45 of the insertion hole 4, and further in consideration of the manufacture of the molding die for forming these, the proper angle is determined.
[0035]
Next, FIG. 5 is a diagram showing an example of a mold for producing a multi-fiber optical connector 1 of the embodiment (1) as a reference example. Here, a state where the mold 8 is assembled is shown. The mold 8 is configured by incorporating a plurality of mold members inside the main body member 81. First, a core member 82 for arranging and holding a plurality of forming pins 83 is provided near the center of the main body member 81. The core member 82 is formed with through holes 822 corresponding to the pitch of the insertion holes 4 of the multi-fiber optical connector 1, and from each through hole 822, the small-diameter portion 47, the taper portion 46, A molding pin 83 in which a small-diameter portion 833, a tapered portion 832, and a large-diameter portion 831 having outer diameters corresponding to the large-diameter portion 45 are formed. Further, a cover member 85 for receiving the other end of the forming pin 83 is provided at the end of the main body member 81. A second core member 86 is disposed and positioned on the opposite side of the end surface 821 of the core member 82 .
[0036]
Since the multi-core optical connector 1 of the present invention does not require a guide groove or a shelf protruding from the insertion hole 4, it is not necessary to put a spacer between the molding pins 83, and the molding pins 83 can be arranged with high density. And in order to form the insertion surface 5, it is only necessary to make the end surface 821 of the core member 82 on the side from which the forming pin 83 protrudes into an inclined surface. As described above, the inclination angle of the end face 821 (θ in FIG. 5) is smaller, and the inclination of the insertion face 5 becomes gentler as the value is smaller, and d and D in FIG. Workability during insertion is improved. However, if θ decreases, the through hole 822 of the core member 82 becomes longer (deeper) even if the number of the insertion hole rows 40 is the same, so that the processing accuracy to be managed when manufacturing the through holes 822 becomes severe. Therefore, the angle θ is determined in consideration of both the ease of manufacturing the core member 82 and the ease of viewing the insertion hole 4.
[0037]
As a method of manufacturing the multi-fiber optical connector 1, the mold 8 is formed by combining the main body member 81, the core member 82, the molding pin 83, the cover member 85, and the second core member 86, and the resin is formed in the gap. The shape shown in FIG. 1 is molded through predetermined molding conditions. Then, the multi-fiber optical connector 1 is taken out from the mold 8, but at this time, since there is no thin guide groove or the like as in the prior art, there is no fear that the yield will be deteriorated due to breakage during drawing.
[0038]
【The invention's effect】
As described above in detail, the multi-fiber optical connector according to the present invention can insert an optical fiber while reliably viewing the insertion hole from the opening by tilting the insertion surface on which the insertion hole is formed. In addition, since the insertion hole itself can be used as a guide, workability during insertion can be greatly improved.
[0039]
In addition, since the insertion surface is only inclined, even if the number of insertion holes of the optical fiber increases in multiple stages, if the insertion work is performed sequentially from the lower side, there are rows that are difficult to work and rows that are difficult to see. It does not occur. Therefore, the number of rows of insertion holes can be increased without worrying about workability, and the density can be increased.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a reference example of a multi- fiber optical connector.
FIG. 2 is an external view of a reference example of a multi- fiber optical connector.
FIG. 3 is an explanatory view showing an operation of inserting an optical fiber in a multi- fiber optical connector.
FIG. 4 is a cross-sectional view of the insertion surface of the embodiment (1).
FIG. 5 is a cross-sectional view of a mold advantageous for manufacturing the multi-fiber optical connector according to the embodiment (1).

Claims (5)

In the internal space of the ferrule for receiving an optical fiber, while the insertion surface with insertion holes of the optical fiber of the plurality of rows Ru is formed to be inclined to the arrangement direction of the column communicates with said internal space and the outside, and the In a multi-fiber optical connector in which an opening is formed at a position where the insertion holes can be visually recognized, the cut-out angle of the remaining insertion surface between the insertion holes is determined from the cut-out angle of the insertion hole formed according to the inclination of the insertion surface. Is a multi-fiber optical connector formed so as to be large.   2. The multi-fiber optical connector according to claim 1, wherein the slope of the insertion surface is formed so as to protrude from a position close to the opening to a position far from the opening.   3. The multi-fiber optical connector according to claim 1, wherein when the insertion hole faces the opening, at least a part of the circumference of the insertion hole is visually recognized as an optical fiber insertion guide. .   4. The multi-fiber optical connector according to claim 1, wherein the insertion hole has a small-diameter portion for supporting the inserted optical fiber and a large-diameter portion positioned on the insertion surface side and having a larger inner diameter than the small-diameter portion. A multi-fiber optical connector having a diameter portion.   5. The multi-fiber optical connector according to claim 1, wherein the opening portion is also used as an addition port for an adhesive added to fix the optical fiber.

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