JPH09159867A - Optical connector and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adequately and easily set both the drawing-out resisting force between a connector main body and an optical fiber and an increase in transmission loss caused when the connector main body is crimped onto the optical fiber. SOLUTION: To fix the connector 30 which has a ferrule 1 supporting the tip part of an optical fiber 5 to the tip part of an optical cord 31 formed by coating the outer peripheral surface of the optical fiber 5 with a jacket material 6 and a sheath material 8 concentrically in this order, a crimp ring 3 is previously built in at least one of a connector main body 2 and the ferrule 1 or a hole 2b through which part of the crimp ring 3 is seen is formed in at least one of the connector main body 2 and the ferrule 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of communication equipment using an optical fiber coat, and more particularly to improvement of an optical connector and its manufacturing method.

[0002]

2. Description of the Related Art In recent years, quartz-type optical fiber cords have been put into practical use in various communication lines in place of conventional so-called twisted pair wires such as metal wires. Then, as a method of connecting such a silica-based optical fiber cord, a short optical fiber is connected to the optical connector in advance, and the tip of this optical fiber and the optical fiber cord laid at the site are butted to each other and the arc discharge device is used. The method of fusing is adopted. However, since the arc discharge device is large, it is difficult to carry the arc discharge device and the construction cost is high.

As a means for solving this, there is a so-called adhesive type optical connector in which an optical connector and an optical fiber are integrated with an adhesive. FIG. 22 is a vertical cross-sectional view showing a state in which the optical fiber 23 is adhesively fixed inside the adhesive connector 18. As shown in the drawing, the optical fiber 23 and the sheath material 8 are inserted to a predetermined position inside the through hole 20a provided in the optical connector main body 20 and fixed by the organic adhesive 21. Since such an adhesive type optical connector 18 fixes the optical fiber 23 with an organic adhesive, it takes a long time to inject and cure the adhesive, and the adhesive protrudes from the tip of the ferrule, resulting in extra protrusion. After cutting the optical fiber 23, it is necessary to polish the ferrule tip. However, this polishing requires a high technique, and has a problem that workability is poor.

As a means for solving this problem, a so-called pressure-bonding type optical connector, which does not require an organic adhesive for fixing an optical fiber, has recently been proposed and put into practical use. An example of such a conventional pressure-bonding type optical connector is shown in Japanese Utility Model Laid-Open No. 63-88803. Hereinafter, this will be described with reference to FIG. FIG. 23 shows a conventional crimp type optical connector 19, which is a connector body 2
After inserting the internal optical fiber 23 of 0, the connector body 2
It is a longitudinal cross-sectional view of a state in which a force in the direction of the arrow shown in the drawing is applied from the outer peripheral portion of 0 to crimp and fix. That is, as shown in the figure, the through hole 2 formed inside the optical connector body 20.
The crimp sleeve 22 is previously inserted and fixed to a part of 0a. Next, the optical fiber 23 and the sheath material 8 whose coating has been stripped off by a predetermined length are inserted into the connector body 20, and the crimp sleeve 2 is inserted from the outside of the optical connector body 20.
2. The optical connector 23 and the optical fiber 23 are integrated by crimping and fixing the right side of the optical fiber 23 and the portion where the sheath material 8 is located.

[0005]

In such a crimp type optical connector 19, the crimping force to the optical fiber 23 satisfies the mechanical pulling-out strength of the optical fiber and increases the loss of the optical fiber caused by crimping (crimping). Therefore, stress is applied to the optical fiber 23, and the propagation of light is impeded.) Must be set within a desired range.

However, as described above, the connector body 20
It is very difficult to satisfy both of the above-mentioned parameters of pull-out proof strength and loss increase by crimping from outside. In addition, when crimping a silica-based optical fiber, it is more difficult to satisfy the above parameters. In some cases, even if the loss increase amount is satisfied, the pull-out proof strength may not be satisfied, resulting in an extremely low reliability optical connector. There is a problem that becomes. That is, the connector 19 assembled by crimping after setting a predetermined loss increase amount is
When the temperature cycle test prescribed in 5961 is performed, pistening between the sheath material 8 and the optical fiber 23 (the entry and exit of the optical fiber wire due to the difference in the coefficient of linear expansion) occurs, and the pulling-out proof strength is greatly reduced. There is a problem that 23 is missing. On the other hand, when the pressure-bonding force is increased to assemble so as to satisfy the pulling-out proof strength, there is a problem that the predetermined loss increase amount is greatly exceeded, and the optical connector has a very low reliability.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to easily set the crimping force of the optical fiber to the connector body to an appropriate one, thereby increasing the transmission loss of the optical fiber and pulling-out proof stress. It is an object of the present invention to provide an optical connector and a method for manufacturing the same, which can set and to an appropriate value.

[0008]

In order to achieve the above object, the tip end portion of an optical cord in which a coating material and a sheath material are concentrically coated in this order on the outer peripheral surface of an optical fiber element according to claim 1, In an optical connector in which a connector body having a ferrule for supporting the tip end of the optical fiber strand is fixed, a crimp ring for crimping the optical fiber strand is previously provided in at least one of the connector body and the ferrule. It is characterized in that it is internally provided with a hole through which a part of the crimp ring is seen.

In the optical connector according to a third aspect of the present invention, the tip end of the optical fiber wire is attached to the tip end of an optical cord in which the outer peripheral surface of the optical fiber wire is concentrically covered with a coating material and a sheath material in this order. In an optical connector having a fixed connector body having a supporting ferrule, a polygonal groove for fixing the optical fiber strand is provided along the center of the connector body, and a part of the connector body including at least one side of the polygonal groove Is configured to be divisible.

The optical connector of claim 1 or 3 uses a ferrule that concentrically supports the exposed tip of the optical fiber strand and a connector body that fixes the ferrule, and the crimp ring is It is preferable to use one that is internally provided in at least one of the ferrule and the connector body. In addition, as the optical cord, a reinforcing material is further concentrically covered between the covering material and the sheath material, and the front end portion of the reinforcing material surrounds the rear end portion of the connector body and It is preferable to provide a sleeve that fixes both the tip portion and the tip portion of the sheath material.

As the material of the optical fiber to which the present invention can be applied, the outer circumference of a core made of quartz may be covered with a quartz clad, and in this case, the clad is made of a hard synthetic resin. Good. Also, as the structure of the optical fiber, multimode step index type, multimode graded index type,
Either a single mode zero dispersion type or a single mode dispersion flat type may be used. The hard synthetic resin is not particularly limited as long as it has a Shore D hardness of 50 or more, but an ultraviolet curable resin such as urethane acrylate or fluorinated acrylate is more preferable.

According to a seventh aspect of the present invention, there is provided an optical connector manufacturing method, wherein a connector body having a ferrule for concentrically supporting the tip end of the optical fiber wire and a crimp ring for fixing the optical fiber wire are provided in the connector body, or An optical connector that is pre-installed in at least one of the ferrules and has a hole through which a part of the crimp ring is seen in at least one of the connector body or the ferrule, and the optical fiber strand. After covering the outer peripheral surface of the optical cord, in which the coating material and the sheath material are concentrically coated in this order, the optical fiber element wire and the coating material are exposed for a predetermined length in this order, and after being inserted into the connector body. The first crimping portion is formed by crimping the crimping ring that is viewed through the hole, and the optical fiber element wire and the crimping ring are connected together. The connector main body, and then insert a sleeve into the rear end of the connector main body to further superimpose the sleeve front end on the rear end of the connector main body, and then crimp the sleeve front end. It is characterized in that the optical fiber element wire, the crimp ring, the connector body and the sleeve are integrated at the same time by forming the crimp portion 2.

In the method of manufacturing an optical connector according to claim 7, the sleeve is integrated with the sheath material by forming a second crimp portion and then crimping a rear end portion of the sleeve to form a third crimp portion. In this case, it is preferable to simultaneously form the second pressure-bonding portion and the third pressure-bonding portion. Further, it is preferable that the crimp ring is crimped between two planes that sandwich the optical fiber strand.

According to the eleventh aspect of the present invention, there is provided a method of manufacturing an optical connector in which a connector body having a ferrule for concentrically supporting the tip end of the optical fiber strand and a plurality of the optical fiber strands fixed along the center of the connector body. An optical connector is provided with a rectangular groove and a part of a connector body including at least one side of the polygonal groove is dividable, and a coating material and a sheath material are concentric in this order on an outer peripheral surface of the optical fiber wire. The tip portion of the optical cord covered with the optical fiber element wire, the covering material is exposed for a predetermined length in this order, after being inserted into the connector body, the optical fiber element wire is temporarily fixed by the polygonal groove, Then, the sleeve is inserted into the rear end of the connector main body, and the sleeve front end is further laid on the rear end of the connector main body. By forming the second crimp portion and crimped ends, and characterized in that integrated optical fiber elements, the connector body and the sleeve simultaneously.

In the method for producing an optical connector according to claim 11, the sleeve is integrated with the sheath material by forming the second crimp portion by crimping the rear end portion of the sleeve after forming the first crimp portion. In this case, it is preferable to simultaneously form the first pressure-bonding portion and the second pressure-bonding portion. In the present invention, the tip portion means
The side where the ferrule is installed (the left side in Figure 1)
The rear end portion means the opposite side.

[0016]

According to the optical connector of claim 1, a crimp ring for crimping an optical fiber wire is pre-installed in at least one of the connector body and the ferrule, and the connector body or the ferrule is provided. Since at least one of them has a hole through which part of the crimp ring can be seen, it is possible to crimp the crimp ring directly, not through the connector body or ferrule, and easily set the amount of deformation of the crimp ring in advance. Therefore, it is possible to easily achieve the increase in loss of the optical fiber caused by crimping within a desired range while satisfying the mechanical pulling-out strength of the optical fiber.

According to the optical connector of claim 3, a polygonal groove for fixing the optical fiber strand is provided along the center of the connector body, and a part of the connector body including at least one side of the polygonal groove can be divided. Therefore, it is possible to fix the optical fiber strands evenly, and it is easy to achieve the increase in optical fiber loss caused by crimping within the desired range while satisfying the mechanical pulling strength of the optical fiber. it can.

According to the seventh aspect of the present invention, there is provided a method of manufacturing an optical connector, wherein the tip end portion of the optical cord is formed by concentrically covering the outer peripheral surface of the optical fiber element with a coating material and a sheath material in this order.
After exposing the optical fiber wire and the covering material for a predetermined length in this order and inserting them into the connector body, the crimp ring seen through the hole is crimped to form a first crimp portion,
The optical fiber wire, the crimp ring, and the connector body are integrated, and then the sleeve is inserted into the rear end portion of the connector body, and the sleeve tip portion is further stacked on the rear end portion of the connector body. By crimping the tip to form the second crimp, the optical fiber strand, crimp ring, connector body and sleeve can be integrated at the same time, so all the components of the optical connector can be easily integrated at the same time. As a result, the assembly work time of the optical connector can be further shortened.

According to the optical connector manufacturing method of the eleventh aspect of the present invention, the tip end of the optical cord formed by concentrically covering the outer peripheral surface of the optical fiber wire with the coating material and the sheath material in this order is After exposing the coating material in the order of a predetermined length and inserting it into the connector body, the optical fiber strand is temporarily fixed in the polygonal groove, and then a sleeve is inserted into the rear end of the connector body to form the connector body. Overlay the sleeve tip on the rear end,
Then, the tip of the sleeve is crimped to form the second crimped portion, whereby the optical fiber element wire, the connector body, and the sleeve are integrated at the same time. Therefore, all the constituent members of the optical connector can be easily integrated at the same time. As a result, it is possible to further reduce the assembly work time of the optical connector.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a vertical sectional view of an embodiment of the optical connector according to the present invention. First, an outline of the optical connector 30 of this embodiment will be described. The ferrule 1 for holding the optical fiber strand 5 in a substantially concentric manner is integrated with the left end portion 2c of the connector body 2 by fitting, and the optical fiber strand 5 to be inserted is inserted in the central portion of the connector body 2. The hole is slightly larger than that. In addition, a crimp ring 3 for crimping the inserted optical fiber strand 5 is preliminarily inserted in substantially the center of the connector body 2, and the crimp ring 3 is directly crimped from the outside of the connector body 2. A hole 2b is provided for this purpose.

On the other hand, the coating of the optical cord 31 is peeled off, the optical fiber strand 5, the secondary coating material 6, and the reinforcing material 7 such as Kevlar are exposed to a predetermined length, and the rear end portion 2a of the connector body 2 is exposed.
Insert more to the left in the figure. Next, the connector body 2
The crimp ring 3 is crimped by applying a force in the direction of the arrow from the hole 2b of FIG. 1 to be integrated with the optical fiber strand 5 (see crimp A).

Next, the outer periphery of the rear end portion 2a of the connector body 2 is covered with a reinforcing material 7 such as Kevlar, and the sleeve 4 is further covered on the outer surface thereof, and then pressure is applied by applying force in the direction of the arrow in the figure ( (Refer to the crimping B), the rear end portion 2a of the connector body, the secondary covering material 6 and the reinforcing material 7 are integrated. On the other hand, at the rear end portion 4b of the sleeve 4, a force in the direction of the arrow in the drawing is applied thereto to crimp the sheath material 8 of the optical fiber cord (see crimping C) to integrate both members.

The outline of the optical connector of this embodiment has been described above. Next, the assembling sequence of the optical connector, which is a feature of the present invention, will be described in detail with reference to FIGS. 2 to 6. As shown in FIG. 2, the core 10 and the clad 11 each have an outer diameter of 5
An optical fiber composed of 0 μm and 100 μm quartz, and a hard synthetic resin 12 with an outer diameter of 125 μm.
The optical fiber strand 5 is further coated with a primary coating material 9 having an outer diameter of 400 μm, a secondary coating material 6 having an outer diameter of 900 μm, a reinforcing material 7, and a sheath material 8, which are made of one or more layers of synthetic resin. The coating is stripped off for a predetermined length at the end of the optical cord 31 formed by the above. FIG. 2 is a perspective view of this state.

Next, as shown in FIG. 3, from the rear end portion (right side in FIG. 3) of the connector body 2 which is integrated with the ferrule 1 and the crimp ring 3 by fitting or the like, a coating is performed as shown in FIG. The stripped optical cord 31 is inserted. Next, a tool (not shown) is brought into contact with the hole 2b of the connector body 2,
Crimp the crimp ring. As a result, the connector body 2
The optical fiber strand 5 is fixed to the. FIG. 4 shows the details of this crimping method. FIG. 4A is a cross-sectional view near the hole 2b of the connector body 2. An optical fiber strand 5 is inserted into a central hole 3a of a crimp ring 3 integrated with the connector body 2. From the hole 2b of the connector body 2 to the tool 3
6a and 36b are brought into contact with each other and pressure-bonded as shown in FIG.

As shown in FIG. 4A, the pressure-bonding ring 3 has a substantially circular cross-sectional shape before pressure bonding, and as shown in FIG. When crimping in a cross-sectional shape sandwiched between two parallel planes,
Since the tool may be a biplanar pin shape that sandwiches the crimp ring 3, the shape of the tool required for crimping can be made extremely simple. Further, by controlling the height at the time of crimping (see H in the figure), it is possible to keep the mechanical strength of pulling out the optical fiber strand 5 from the crimp ring 3 and the increase in optical fiber loss caused by crimping within a desired range. Becomes very easy.

Since the crimping method described above has a structure in which the pull-out force and the increase in loss can be easily set by controlling the height (H) during crimping, the crimp ring 3 before being crimped The outer diameter is not particularly limited, but is preferably about 2 to 10 times the outer diameter of the optical fiber strand 5. It is needless to say that the inner diameter of the crimp ring 3 before crimping should have a clearance as small as possible with respect to the outer diameter of the optical fiber strand 5, and in the case of a particularly large clearance, the optical fiber strand 5 is crimped at the time of crimping. Considering that it may meander inside the center hole 3a of the ring 3 and increase the loss of the optical fiber strand 5 due to a small bend (the loss at this time is particularly referred to as microbend loss), the clearance may be the optical fiber. It is preferable that the outer diameter of the strand 5 is about 1 μm to 100 μm. Furthermore, it is more preferable to set the clearance to about 1 μm to 20 μm.

The material of the crimp ring 3 is preferably a soft metal such as copper, copper alloy, aluminum or aluminum alloy. The shape of the hole 2b of the connector body 2 is preferably circular, but is not limited to this and may be rectangular. Next, as shown in FIG. 5, the rear end portion 2a of the connector body 2 is covered with the reinforcing material 7, and then the sleeve 4 which is previously passed through the sheath material 8 is further covered. Here, a second crimping (refer to crimping B) is performed by applying a force from the direction of the arrow to the sleeve tip portion 4a with a crimping tool (not shown), and the connector body rear end portion 2a and the secondary coating material 6, The reinforcing material 7 and the sleeve tip portion 4a are integrated. The pressure-bonding shape at this time is preferably a hexagon in which the deforming force by the pressure-bonding B is dispersed substantially evenly, but other polygons or circular in some cases may be used. Further, in order to completely fix the secondary coating material 6, it is necessary that the deformation force by the crimping B reaches the rear end portion 2a of the connector body 2 sufficiently. 2a
Is preferably mechanically weaker than the other parts, and in some cases, a slit may be formed in the longitudinal direction to facilitate deformation.

Finally, as shown in FIG. 6, the sleeve rear end portion 4
A third pressure bonding (see pressure bonding C) is performed by applying a force to the b from the direction of the arrow in the figure to integrate the sleeve rear end portion 4b and the sheath material 8. The crimping shape at this time is the same as that of the crimping B and is preferably a hexagon, but may be another polygon or a circle depending on the case. Further, the extra optical fiber strand 5 protruding from the ferrule 1 is cut by a known fiber cutting machine. The second crimp (see crimp B) and the third crimp (see crimp C) shown in FIGS. 5 to 6
Can also be done at the same time. As a result, the assembly work time can be further shortened.

The crimp ring 3 can be built in the ferrule 1 instead of the connector body 2. This state is shown in FIG. The crimp ring 3 previously built in the ferrule 1 is crimped from the hole 1a of the ferrule 1.
This makes it possible to simplify the shape of the connector body 2. Also, the crimp ring 3 is the connector body 2
It can also be built into both ferrule 1. This state is shown in FIG. The crimp ring 3a which is built in the ferrule 1 in advance is crimped from the hole 1a of the ferrule 1 (crimp A
1)), and the crimp ring 3b previously built in the connector body 2 is crimped from the hole 2b of the connector body 2 (see crimping A2). As a result, the number of crimp points of the optical fiber strand 5 can be increased, so that the mechanical pull-out resistance of the optical fiber strand 5 with respect to the connector body 2 can be easily improved.

Further, the crimp rings 3a and 3b can be integrated as shown in FIG. That is, ferrule 1
The tip of the crimp ring 3 is crimped through the hole 1a of
Further, the rear end of the crimp ring 3 is crimped from the hole 2b of the connector body 2 (see crimp A2). As a result, the number of crimp points of the optical fiber strand 5 can be increased, so that the mechanical pull-out resistance of the optical fiber strand 5 with respect to the connector body 2 can be easily improved.

As a method of crimping the crimp ring 3,
As described above, in addition to crimping in a cross-sectional shape sandwiched between two planes substantially parallel to the direction of the optical fiber strand 5, it was sandwiched from four directions as shown in FIGS. 12 (a) and 12 (b). The cross-sectional shape may be good, and in this case, the shape of the tool required for crimping becomes slightly complicated, but since crimping deformation can be made substantially uniform over the entire circumference of the optical fiber strand 5, the mechanical optical fiber strand 5 for the connector body 2 It is possible to easily improve the pull-out proof strength of the.

The optical connector assembled as shown in FIG. 1 was manufactured by the method shown in JIS C5961 (1993).
Insertion loss (including all losses such as loss increase due to crimping, loss due to ferrule accuracy) was measured. The result is shown in FIG. As is apparent from FIG. 7, according to the optical connector of the present invention, the insertion loss is 0.2 to 0.6.
It was within the range of dB, and the average value was 0.38 dB, which was a good result. Further, the pulling-out proof strength of the optical fiber wire 5 at this time was 1 kgf or more, which was good.

[0033]

Comparative Example Next, as a comparative example, the connector structure is the same as that described in FIG. 23, but the crimping method is performed from outside the connector body without performing the crimping steps A to C of the present invention. A conventional crimp-type optical connector that has been crimped was manufactured, and the insertion loss was measured by the same method as in the above embodiment. The insertion loss in this case is shown in FIG. As is clear from FIG. 8, the insertion loss is 0.2 to 0.8d.
It spread to the range of B, and the average value was 0.56 dB, which was 0.18 dB larger than the average value in FIG. 7. Further, the pulling-out proof strength of the optical fiber wire 5 at this time was set to 1 Kgf as in the embodiment, and crimping was performed. It can be seen that when the pulling proof strength is set to the same level as described above, the insertion loss is deteriorated.

FIG. 13 is a vertical sectional view of another embodiment of the optical connector according to the present invention. First, an outline of the optical connector 30 of this embodiment will be described. The same components as those in the embodiment of FIG. 1 are designated by the same reference numerals. The ferrule 1 for holding the optical fiber strand 5 in a substantially concentric manner is integrated with the left end portion 2c of the connector body 2 by fitting, and the optical fiber strand 5 to be inserted is inserted in the central portion of the connector body 2. A larger hole is provided.

In the rear end portion 2a of the connector body 2, a triangular groove 32a for fixing the inserted optical fiber element wire 5 and a semicircular groove 33a for fixing the secondary coating 6 are formed.
Is provided. Further, the flat surface 35a and the semi-circular groove 3 are provided at positions facing the triangular groove 32a and the semi-circular groove 33a.
A pressure contact member 35 having 5b is provided. On the other hand, the coating of the optical cord 31 is peeled off, and the optical fiber strand 5, the secondary coating material 6, and the reinforcing material 7 such as Kevlar are exposed to a predetermined length, and the rear end portion 2a of the connector body 2 is moved to the left in the figure. insert. Next, the pressure contact member 35 is brought into contact with the rear end portion 2a of the connector body 2, and further the reinforcing member 7 is provided so as to surround them.
Then, after further covering the outer side with the sleeve 4, pressure is applied to the tip end side 4a of the sleeve 4 in the direction of the arrow in the figure to perform crimping (see crimping A), and the connector body 2, the optical fiber element wire 5, and the press-contact member 35. , And the reinforcing material 7 are integrated.

On the other hand, at the rear end portion 4b of the sleeve 4, a force in the direction of the arrow is applied to the sleeve 4 to crimp the sheath material 8 of the optical fiber cord (see crimping B) to integrate both members. The above is the outline of the optical connector of the present embodiment.
Next, the assembly sequence of the optical connector, which is a feature of the present invention, will be described in detail with reference to FIGS. As shown in FIG. 2, an optical fiber having a core 10 and a clad 11 made of quartz having outer diameters of 50 μm and 100 μm, respectively, and a hard synthetic resin 1 having an outer diameter of 125 μm.
2, the optical fiber strand 5 is further coated with a primary coating material 9 having an outer diameter of 400 μm, a secondary coating material 6 having an outer diameter of 900 μm, a reinforcing material 7, and a sheath material 8 which are made of one or more synthetic resins. The coated optical cord 31 is stripped to a predetermined length. FIG. 2 is a perspective view of this state.

Next, as shown in FIG. 14, from the rear end portion (right side) of the connector main body 2 which is integrated with the ferrule 1 and the pressure contact member 35 by fitting or the like, as shown in FIG. The optical code 31 is inserted. Next, the pressure contact member 35
And the optical fiber 5 is temporarily fixed. FIG. 15 shows the details of the pressure contact member 35. FIG. 15 is a perspective view of the connector body 2 as seen from the vicinity of the rear end portion 2a. At the rear end portion 2a of the connector body 2, a triangular groove 32a for fixing the optical fiber strand 5 and a semi-circular groove 3 for fixing the secondary coating 6 are formed.
3a are provided respectively, and the press contact member 35 is provided with a flat surface 35a and a semi-circular groove 35b at positions facing the triangular groove 32a and the semi-circular groove 33a.

Next, as shown in FIG. 16, the connector body 2
The rear end portion 2a and the pressure contact member 35 are covered with a reinforcing material 7 so as to surround the optical fiber element wire 5 and the covering material 6, and further with a sleeve 4 on the outer side thereof, and a tip end side 4a of the sleeve 4 is a known tool (not shown). Then, the connector main body 2, the optical fiber element wire 5, the pressure contact member 35, and the reinforcing material 7 are integrated by applying pressure in the direction of the arrow in the figure to perform pressure bonding (see pressure bonding A).
The crimping shape of the tool required for crimping is not particularly limited, but a tool 34 having a substantially circular shape as shown in FIG. 17 is preferable. The size of the triangular groove for fixing the optical fiber element 5 is preferably a regular triangle circumscribing the clad outer diameter (100 μm in this embodiment) of the optical fiber element 5. As a result, the force applied to the fixed optical fiber strand 5 is made uniform, and it becomes very easy to keep the mechanical pull-out strength of the optical fiber strand 5 and the increase in optical fiber loss caused by the fixing within a desired range. .

Since the crimping method described above has a structure in which the pull-out proof strength and loss increase can be easily set by controlling the dimensions of the triangular groove, the length of the triangular groove (L in FIG. 18). Is not particularly limited, but is preferably 10 to 10 of the outer diameter of the optical fiber element wire 5.
It is preferably formed about 100 times. The material of the connector body 2 and the pressure contact member 34 is preferably resin, but is not limited to this, and non-ferrous alloys such as copper and aluminum, stainless steel, and iron can also achieve the object of the present invention. It is a thing.

Finally, as shown in FIG. 18, the sleeve rear end 4
A second pressure (see pressure bonding B) is applied to b in the direction of the arrow in the figure to integrate the sleeve rear end 4b and the sheath material 8. The pressure-bonding shape at this time is preferably a hexagon, but may be another polygon or a circle depending on the case. Further, the extra optical fiber strand 5 protruding from the ferrule 1 is cut by a known fiber cutting machine. The first crimping (see crimping A) and the second crimping (see crimping B) shown in FIGS. 16 to 17 can be performed simultaneously. As a result, the assembly work time can be further shortened.

Further, the groove shape for fixing the optical fiber element 5 is a triangle in the present embodiment, but is not limited to this and may be a quadrangle as shown in FIGS. 20 and 21, or may be a polygon. For example, since a uniform force is applied to the optical fiber strand 5, the increase in loss due to crimping can be minimized, and the reliability of the optical connector can be improved.

The optical connector assembled as shown in FIG. 13 was measured for insertion loss (including all loss such as loss increase due to crimping, loss due to ferrule accuracy) by the method described in JIS C5961 (1993). The result is shown in FIG. As is apparent from FIG. 19, according to the optical connector of the present invention, the insertion loss is in the range of 0.2 to 0.6 dB, and the average value is 0.38.
It was dB, which was a good result. Further, the pulling-out proof strength of the optical fiber wire 5 at this time is 1 kgf or more,
It was good.

By comparing this result with the result of the comparative example, it can be seen that the insertion loss can be reduced in the present embodiment when the pulling-out proof strength is set to the same level. In addition,
In any of the above embodiments, the connector type is JI
The F09 type single-core optical fiber connector (JIS C5970) and the F02 type single-core optical fiber connector (JIS C5971) are shown without limitation to the F09 type single-core optical fiber connector specified in S C5978 (1993). ), F03 type single core optical fiber connector (JIS C5972) and other single core connectors, F07 type double core optical fiber connector (J
It is also sufficiently applicable to a two-core connector such as IS C5976) and F08 type two-core optical fiber connector (JIS C5977).

[0044]

According to the first aspect of the present invention, the crimp ring can be directly crimped, not through the connector body or the ferrule, and the deformation amount of the crimp ring can be easily set in advance, and mechanically. The peculiar effect that it is possible to easily achieve the increase in the loss of the optical fiber caused by the crimping within a desired range while satisfying the pulling-out proof strength of the optical fiber.

The invention of claim 2 has the same effect as that of claim 1. According to the invention of claim 3, it is possible to fix the optical fiber strands uniformly, and thus it is easy to keep the increase in loss of the optical fiber caused by crimping within a desired range while satisfying the mechanical pull-out resistance of the optical fiber. It has a unique effect that can be achieved.

The invention of claim 4 is from claim 1 to claim 3.
The same effect as any of the above. The invention of claim 5 is
The same effect as that of any one of claims 1 to 3 is achieved. The invention of claim 6 has the same effect as that of any one of claims 1 to 3. The invention of claim 7 has a unique effect that all the constituent members of the optical connector can be easily integrated almost at the same time, and the assembling time of the optical connector can be shortened.

The invention of claim 8 has a unique effect that all the constituent members of the optical connector can be easily integrated almost simultaneously and the assembling work time of the optical connector can be shortened. The invention of claim 9 has a unique effect that the number of times of crimping can be made a total of two times and the assembling work time of the optical connector can be further shortened.

According to the tenth aspect of the invention, since the crimping is performed between the two planes sandwiching the crimping ring, the shape of the jig required for crimping can be made into an extremely simple biplanar pin shape, and as a result, the crimping height can be increased. It is possible to easily control the thickness, satisfy the mechanical pulling-out strength of the optical fiber, and easily achieve the increase in the loss of the optical fiber caused by crimping within a desired range.

According to the eleventh aspect of the present invention, all the constituent members of the optical connector can be easily integrated almost at the same time, and the assembly work time of the optical connector can be further shortened. Claim 1
The second aspect of the invention has a unique effect that all the constituent members of the optical connector can be easily integrated almost simultaneously and the assembling time of the optical connector can be shortened.

The thirteenth aspect of the invention has a unique effect that the number of times of crimping can be made once in total and the assembling time of the optical connector can be further shortened.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of an embodiment of an optical connector according to the present invention.

FIG. 2 is a perspective view of the optical cord of FIG. 1 with a coating removed.

FIG. 3 is a first vertical sectional view showing an assembling sequence of the optical connector of FIG.

4 is a cross-sectional view showing a crimped shape of the crimp ring of FIG.

5 is a second vertical sectional view showing the assembling order of the optical connector of FIG. 1. FIG.

6 is a third vertical cross-sectional view showing the assembly sequence of the optical connector of FIG.

FIG. 7 is a graph showing a distribution of insertion loss of the optical connector according to the present invention of FIG.

FIG. 8 is a graph showing the distribution of insertion loss of a conventional crimp type optical connector.

FIG. 9 is a vertical sectional view showing another embodiment of the optical connector according to the present invention.

FIG. 10 is a vertical sectional view showing another embodiment of the optical connector according to the present invention.

FIG. 11 is a vertical sectional view showing another embodiment of the optical connector according to the present invention.

FIG. 12 is a cross-sectional view showing a crimped shape of a crimp ring of another embodiment of the optical connector according to the present invention.

FIG. 13 is a vertical cross-sectional view of another embodiment of the optical connector according to the present invention.

FIG. 14 is a first vertical sectional view showing an assembly sequence of the optical connector of FIG.

15 is a perspective view of the optical connector of FIG. 14 in the vicinity of a pressure contact member.

16 is a second vertical sectional view showing the assembly sequence of the optical connector of FIG.

FIG. 17 is a sectional view of a fixed portion of the optical fiber of FIG.

FIG. 18 is a third vertical sectional view showing the assembly sequence of the optical connector of FIG.

FIG. 19 is a graph showing distribution of insertion loss of the optical connector of FIG.

FIG. 20 is a vertical sectional view showing another embodiment of the optical connector according to the present invention.

FIG. 21 is a vertical cross-sectional view showing another embodiment of the optical connector according to the present invention.

FIG. 22 is a vertical cross-sectional view of a conventional adhesive type optical connector.

FIG. 23 is a vertical sectional view of a conventional crimp type optical connector.

[Explanation of symbols] 1 ferrule 2 connector body 3 crimping ring 4 sleeve 5 optical fiber element wire 6 secondary coating material 7 reinforcing material 8 sheath material 9 primary coating material 10 quartz core 11 quartz clad 12 hard resin 30 optical connector 31 optical code 32a groove

Claims (13)

[Claims] 1. A distal end portion of an optical cord (31) in which an outer peripheral surface of an optical fiber element (5) is concentrically coated with a coating material (9) (6) and a sheath material (8) in this order, An optical connector (30) having a fixed connector body (2) having a ferrule (1) for supporting the tip of the optical fiber strand (5), wherein the connector body (2)
A crimp ring (3) for crimping the optical fiber wire (5) is pre-installed in at least one of the inside or the ferrule (1), and a hole through which a part of the crimp ring (3) is seen. (2b) is provided, The optical connector characterized by the above-mentioned. 2. The optical connector according to claim 1, wherein the crimp ring (3) is crimped through the hole (2b) to fix the optical fiber strand (5). 3. An optical cord (31) comprising a coating material (9) (6) and a sheath material (8) concentrically coated in this order on the outer peripheral surface of an optical fiber (5), An optical connector (30) having a fixed connector body (2) having a ferrule (1) for supporting the tip of the optical fiber strand (5), wherein the connector body (2)
A polygonal groove (32a) for fixing the optical fiber wire (5) is provided along the center of the connector, and a part of the connector body (2) including at least one side of the polygonal groove (32a) is dividable. An optical connector that is characterized by 4. The coating (6) for the optical code (31)
A reinforcing material (7) is concentrically coated between the sheath material (8) and the sheath material (8), and the tip of the reinforcing material (7) surrounds the rear end of the connector body (2). The sleeve (4) for fixing both of the tip portion of the reinforcing material (7) and the tip portion of the sheath material (8) is provided, and the sleeve (4) according to any one of claims 1 to 3. Optical connector. 5. The optical fiber according to claim 1, wherein a core (10) made of quartz is coated with a clad (11) made of quartz on the outer periphery of the optical fiber. Optical connector. 6. The optical connector according to claim 5, wherein the clad (11) is made of a hard synthetic resin (12). 7. A connector body (2) having a ferrule (1) for concentrically supporting the tip of an optical fiber strand (5), and a crimp ring (3) for fixing the optical fiber strand (5). The connector body (2) or at least one of the ferrules (1) is pre-installed, and the connector body (2) or at least one of the ferrules (1),
An optical connector (30) having a hole (2b) through which a part of the crimp ring (3) is viewed, and a covering material (9) on the outer peripheral surface of the optical fiber element (5).
(6) and the sheath material (8) are concentrically covered in this order, and the tip portion of the optical cord (31) has a predetermined length in the order of the optical fiber element wire (5) and the covering materials (9) and (6). Only exposed and inserted into the connector body (2), and then crimp the crimp ring (3) seen through the hole (2b) to form a first crimp portion, which is crimped to the optical fiber strand (5). The ring (3) and the connector body (2) are integrated, and then the sleeve (4) is inserted into the rear end portion of the connector body (2) to further sleeve on the rear end portion of the connector body (2). (4) The tip end portions are overlapped with each other, and then the tip end portion of the sleeve (4) is crimped to form a second crimp portion, whereby the optical fiber strand (5), the crimp ring (3), and the connector body (2). ) And sleeves (4)
A method for manufacturing an optical connector, characterized in that both are integrated at the same time. 8. The sleeve (4) is integrated with the sheath material (8) by forming a third pressure-bonding portion by pressure-bonding the rear end of the sleeve (4) after forming the second pressure-bonding portion. The method for producing an optical connector according to claim 7, wherein 9. The method of manufacturing an optical connector according to claim 7, wherein the second crimping portion and the third crimping portion are formed at the same time. 10. Manufacturing of the optical connector according to claim 7, wherein the crimping ring (3) is crimped between two planes sandwiching the optical fiber strand (5). Method. 11. A connector body (2) having a ferrule (1) for concentrically supporting the tip of the optical fiber strand (5), and the optical fiber strand (5) along the center of the connector body (2). ) Fixed polygonal groove (32
The optical connector (30), which is provided with a) and in which a part of the connector body (2) including at least one side of the polygonal groove (32a) is dividable, is provided with an outer peripheral surface of the optical fiber strand (5). Coating material (9)
(6) and the sheath material (8) are concentrically covered in this order, and the tip portion of the optical cord (31) has a predetermined length in the order of the optical fiber element wire (5) and the covering materials (9) and (6). Only exposed and inserted into the connector body (2), the optical fiber strand (5) is temporarily fixed by the polygonal groove (32a), and then a sleeve (on the rear end of the connector body (2)). 4) through which the front end of the sleeve (4) is superposed on the rear end of the connector body (2), and then the front end of the sleeve (4) is crimped to form a second crimped portion. A method for manufacturing an optical connector, characterized in that the optical fiber strand (5), the connector body (2) and the sleeve (4) are integrated at the same time. 12. The sleeve (4) is integrated with the sheath material (8) by forming a second pressure-bonding portion by pressure-bonding the rear end of the sleeve (4) after forming the first pressure-bonding portion. 12. The method for manufacturing an optical connector according to claim 11, wherein the method is used. 13. The method of manufacturing an optical connector according to claim 11, wherein the first crimp portion and the second crimp portion are formed at the same time.