JP2001004862A - Ferrule for optical connector and its manufacture, and optical connector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector having little variation in connection loss even in repeated detaching and attaching, and a ferrule for this optical connector. SOLUTION: This ferrule is used for respectively positioning and fixing both optical fibers 2 by optical connectors C1 performing optical connection by respectively abutting the ends of a pair of optical fibers 2 against their mate ends. In the ferrule body 1A, a connection end 10 is formed at the end side of the optical fibers to be positioned and fixed, and fiber-positioning holes 13, into which the optical fibers are inserted so as to be positioned and fixed, are formed penetrating through the ferrule body 1A from the connection end 10. Near the connection end 10, each of the fiber-positioning holes 13 has an the internal diameter expanding region 14 toward the connection end 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferrule for an optical connector used for connecting an end face of an optical fiber, a method of manufacturing the ferrule, and an optical connector using the ferrule.

[0002]

2. Description of the Related Art As an optical connector for a general multi-core optical fiber, an optical connector of the type standardized in JIS C5981 is known, and this type of optical connector is disclosed in Japanese Patent Application Laid-Open No. 8-179161. It is manufactured using a molding die as disclosed in Japanese Unexamined Patent Publication (Kokai) Publication. This optical connector C is of a type in which an optical fiber is positioned and fixed by a ferrule 1 as shown in FIGS. The ferrule 1 is attached to the end of the optical fiber 2 as shown in FIG. 11, and the joint end face 10 with the mating optical connector C is aligned with the end faces of both connectors. A pair of pin holes 11 into which the guide pins 3 for fixing in place are inserted are provided. These pin holes 11 are formed through the inside of the ferrule 1 from the joint end face 10 to the opposite end face. The end of the fiber arrangement hole 13 for arranging the optical fibers in the optical fiber core wire 2 is also opened in the joint end face 10.
The above-described optical connectors C are positioned with respect to each other by inserting a common guide pin 3 into the pin hole 11, and FIG.
And the clamped spring 5 maintains the connected state of the two.

[0003]

An optical connector of this kind is used for making an optical connection at a place in the optical communication line which needs to be separated or switched. To switch the connection, you need to detach the optical connector.
Optical connectors are required to have a small connection loss variation even after repeated attachment and detachment.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical connector having a small connection loss variation even after repeated attachment and detachment, a ferrule for the optical connector, and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a ferrule for an optical connector according to the present invention comprises an optical connector for optically connecting two optical fibers by abutting end faces of a pair of optical fibers. An optical connector ferrule used for positioning and fixing,
In the ferrule body, a connection end face is formed on the end face side of the optical fiber to be positioned and fixed, and a fiber positioning hole for inserting and positioning and fixing an optical fiber formed through the ferrule body from the connection end face to the inside. These fiber positioning holes are characterized in that they have an enlarged area near the connection end face, the inner diameter of which increases as the distance from the connection end face increases.

In the ferrule for an optical connector according to the present invention, an enlarged area is formed on the connection end face side of the fiber positioning hole such that the inner diameter increases as the connection end face becomes closer. When an optical connector in which the fiber end face is drawn into the ferrule main body from the connection end face using this ferrule is formed, the edge of the opening at the connection end face of the fiber positioning hole is missing due to the detachment. To prevent damage to the ferrule. Another advantage is that the end face of the fiber can be easily cleaned. Conversely, when an optical connector having a configuration in which the fiber end face protrudes from the ferrule main body from the connection end face is formed, it is possible to prevent the fiber from being damaged due to the application of a shearing force to the protruding fiber accompanying the detachment. As a result, it is possible to suppress a change in connection loss due to detachment. These effects are particularly remarkable in a connector in which the optical fiber is not bonded and fixed at the ferrule tip.

[0007] The ferrule body has
A pair of guide holes for inserting guide pins for connecting optical connectors formed toward the inside of the main body are provided, and the guide holes have an enlarged area near the connection end face where the inner diameter increases as the connection end face is closer to the connection end face. It is preferable to have.

In the optical connector using the ferrule, when the guide pin is inserted into the guide hole from the connection end face side, since the inner diameter of the guide hole becomes larger near the connection end face near the connection end face, the guide pin is enlarged. Since the pin is easy to insert and can be inserted smoothly, it is possible to suppress the loss and wear of the ferrule due to the guide pin,
An optical connector that can always maintain good transmission characteristics even after repeated attachment and detachment can be realized.

It is preferable that the wall surfaces of these enlarged regions are formed as conical surfaces or curved surfaces protruding into the holes. This makes it possible to easily and reliably form the enlarged area.

[0010] The diameter of the opening of the fiber positioning hole at the connection end face is preferably not less than 0.13 mm and not more than 0.25 mm. The outer diameter of a general optical fiber is 0.12
By setting the opening diameter in this range, a sufficient enlarged area can be formed.

On the other hand, an optical connector according to the present invention comprises two pairs of optical fibers, a pair of optical connector ferrules according to the present invention for positioning and fixing each pair of optical fibers, and a pair of optical fibers for an optical connector. A pair of guide pins that are inserted into the respective guide holes of the ferrule and connect the two optical connector ferrules. According to this optical connector, it is possible to prevent damage to the optical fiber and the ferrule due to attachment / detachment, and to always maintain good transmission characteristics even after repeated attachment / detachment. It is preferable to be arranged at a position inside the ferrule main body from the connection end face and protruding into the enlarged area of the fiber positioning hole. By arranging the end face of the optical fiber in the enlarged area of the fiber positioning hole, the end face connection can be ensured and the fiber can be effectively prevented from being damaged.

The method of manufacturing a ferrule for an optical connector according to the present invention is a molding pin for forming a guide hole and a fiber positioning hole. A step of arranging a predetermined number of molding pins having an enlarged area that is gradually enlarged in a molding die so as to be slidable in the axial direction, a filling step of filling the resin in the mold, and a step of filling the resin. Forming a ferrule main body having a predetermined guide hole and a fiber positioning hole by pulling out the forming pins in the direction of the base end after solidification.

According to this manufacturing method, when forming the guide hole and the fiber positioning hole in the optical connector ferrule main body, it is possible to easily and surely form an enlarged area on the connection end face side.

[0014]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In order to facilitate understanding of the description, the same constituent elements are denoted by the same reference numerals as much as possible in each drawing, and redundant description will be omitted.

FIG. 1 is an exploded perspective view showing a first embodiment of an optical connector according to the present invention. FIG. 2 is a sectional view of an optical connector ferrule in a state where an optical fiber is not inserted. FIG. 3 is a sectional view of the optical fiber positioning hole in a state where the optical fiber is inserted.

The optical connector C1 is formed by positioning and fixing the tip of a tape-shaped optical fiber core 2 with a ferrule 1A. The ferrule 1A is provided on a joint end face 10 with a mating optical connector C1 for positioning. And a pair of pin holes 11 into which the guide pins 3 are inserted. An enlarged area 1 in which the inner diameter is increased toward the end face by being chamfered in a tapered shape at the open end of the pin hole 11.
2 are formed respectively. In addition, these pin holes 1
1 is a ferrule 1 from the joint end face 10 to the opposite end face.
A is formed through the inside of A.

A fiber positioning hole 1 for positioning and fixing the optical fibers in the tape-shaped optical fiber core 2 one by one between the two pin holes 11 on the joint end face 10 of the ferrule 1A.
3 are arranged at predetermined intervals. Each of the open ends of the fiber positioning holes 13 is also beveled in a tapered shape, thereby forming enlarged regions 14 whose inner diameters are increased toward the end face. An opening 16 for filling the adhesive is opened on the upper surface of the ferrule 1A. The optical fibers are arranged one by one in the fiber positioning holes 13, and the adhesive is filled from the opening 16. By solidifying, each of the arranged optical fibers and the tape-shaped optical fiber core 2, and further,
A boot 4 covering the tape-shaped optical fiber core 2 is fixed to the ferrule 1A.

The enlarged areas 12 and 14 formed at the open ends of the pin hole 11 and the fiber positioning hole 13 respectively include:
As shown in FIG. 2, the inner diameter is increased toward the joint end surface 10, and the inner wall surface has a truncated cone shape. The apex angle of the truncated cone, that is, the chamfer angle α is preferably 30 ° to 70 °.

Each fiber positioning as shown in FIG.
An optical fiber 20 is inserted into the hole 13 and the adhesive 15
Has been fixed by. Therefore, fiber positioning
Inner diameter D of female hole 13₀Is the outer diameter d of the fiber (typically 125
μm) (several μm).
On the other hand, the opening diameter D at the joint end face 10 of the enlarged area 14 ₁
Is D₀Larger, preferably 130 μm to 250 μm
Is preferably set in the range. Opening diameter D₁To
If it is smaller than this range, an effective enlarged area 12 is formed.
It becomes difficult to Also, if you exceed this range
Because the connection between optical fibers may be unstable
It is.

When the end face 21 of the optical fiber 20 is located inside the ferrule main body from the joining end face 10, the joining end face is located at the deepest part of the enlarged area 14, that is, the boundary position A between the fiber positioning hole 13 and the cylindrical area. 10 side,
In other words, it is preferable to arrange in the enlarged area 14. By arranging in this manner, the effect of providing the enlarged region 14 as described later is sufficiently exhibited. In the case of an optical connector for making a PC (Physical Contact) connection, the end face 21 of the optical fiber 20 is connected to the joint end face 1.
It is arranged to protrude from 0.

On the other hand, the distance from the deepest end face of the enlarged area 12 of the guide hole 11 is 0.1 mm to 1.0 mm from the joint end face 10.
It is preferable that If the formation area of the enlarged area 12 from the joint end face 10 is less than 0.1 mm, the end of the guide pin 3 cannot be sufficiently guided, and the enlarged area 1
The vicinity of 2 is likely to be broken by contact with the guide pin 3. Also, if the above-described formation range seems to exceed 1.0 mm,
Since the holding of the guide pin 3 on the joining end face 10 side becomes weak,
There is a possibility that connection loss characteristics may be deteriorated. further,
If the above-mentioned formation range D exceeds 1.0 mm, the maximum inner diameter of the enlarged region 12 becomes too large, so that interference with the fiber positioning hole 13 and an increase in the size of the ferrule 1A itself are required. It is not realistic.

Here, the advantages of the optical connector according to the present invention shown in FIG. 1 and the conventional optical connector shown in FIG. 11 will be described with reference to FIGS.

FIG. 4 is a view for explaining a problem in the case where the optical fiber 20 is arranged inside the joint end face 10 of the ferrule 1A in the conventional optical connector. In the conventional optical connector, the edge 11c at the opening end of the fiber positioning hole 13 is easily damaged by repeating attachment and detachment. If this portion is damaged, not only the strength of the ferrule 1A is deteriorated, but also the member lacking due to the damage may enter the joint portion of the fiber and deteriorate the optical coupling state between the fibers.

In the optical connector according to the present invention, FIG.
As shown in (1), since the opening end is in a so-called chamfered state, chipping of the edge hardly occurs even when attachment and detachment are repeated, and a good optical coupling state can be always maintained.

FIG. 5 is a diagram for explaining a problem in a so-called PC connection connector in which the end face 21 of the optical fiber 20 is arranged to protrude from the joint end face 10 of the connector, contrary to the optical connector of FIG. . When the detachment is repeated with such a connector, the optical fiber 20 is subjected to a force such as shearing or bending and comes into contact with the edge of the open end of the joint end face 10 of the fiber positioning hole 13 and is easily damaged at the portion 20a. And durability cannot be maintained. This problem is remarkable when the adhesive 15 is not filled up to the opening end of the fiber positioning hole 13 as shown in the figure, and the optical fiber 20 is not bonded and fixed at the tip of the ferrule. However, filling the adhesive 15 to the vicinity of the opening end of the fiber positioning hole 13 has a risk that the adhesive 15 may protrude from the joint end face 10, which is not preferable in manufacturing and is difficult to solve.

On the other hand, in the case of the optical connector according to the present invention, the presence of the enlarged region 12 allows the optical fiber 20 and the fiber positioning hole 1 even when a force such as bending or shearing is applied.
Since the contact with the edge at the opening end of the opening 3 can be suppressed, damage to the fiber can be effectively prevented, and durability can be ensured even in the case of repeated attachment and detachment.

FIGS. 6 (a) and 6 (b) show the conventional connector having the structure in which the end face 21 of the optical fiber 20 is disposed inside the connection end face 10 and the optical connector according to the present invention when foreign matter adheres to the end face. It is a figure explaining a situation.

In the state where the optical connector is disconnected, foreign matter easily adheres to the connection end face 10, and it is necessary to perform cleaning before connection. In the conventional optical connector shown in FIG. 6A, if a foreign matter 40 enters the optical fiber positioning hole 13, it is difficult to remove the foreign matter 40. It may remain on top and inhibit photocoupling. On the other hand, in the optical connector according to the present invention, as shown in FIG. 6 (b), the presence of the enlarged area 14 allows removal of the foreign matter 40 as compared with the optical connector of the conventional optical connector shown in FIG. 6 (a). It will be easier.

FIGS. 7A to 7C show the enlarged area 14.
It is sectional drawing which showed the modification of each. The same modification can be adopted for the enlarged area 12 of the guide hole 11. In the embodiment shown in FIG. 7A, the inner wall of the fiber positioning hole 13 is chamfered in a curved shape on the opening end side. In this embodiment, it is possible to more effectively prevent the optical fiber from being damaged due to the contact between the inserted optical fiber and the inner wall surface as compared with the case where the tapered enlarged region is provided.

The forms shown in FIGS. 7B and 7C are modifications of the forms shown in FIGS. 3 and 7A, respectively. However, there is a difference in that there is a cylindrical region 14a that is almost the same. By providing such a cylindrical region 14a, the enlarged region 14 can be reliably provided on the connection end face 10 side of the optical fiber positioning hole 13, which is preferable.

Next, a manufacturing process of the ferrule for an optical connector will be described with reference to FIGS. FIG. 8 is an exploded perspective view of a molding die used for molding the ferrule 1A of the optical connector 1C shown in FIG. 1, and FIG.
FIG. 9 is a sectional view taken along line IX.

This molding die comprises a pair of lower dies 108 and an upper die 109, and a pair of molding pins 101 and four small pins 1 inserted between these dies 108,109.
02 is slidably disposed near the dies 108 and 109. The pair of molding pins 101 are formed on the base end side of the cylindrical portion 110 with an outer diameter substantially equal to the inner diameter of the pin hole 11 in the formed ferrule 1A and with the outer diameter gradually increased. Truncated cone 11
And 1.

On the other hand, between the pair of molding pins 101, the fiber positioning holes 13 in the molded ferrule 1A are provided.
There are provided four small pins 102 for molding the.
As shown in the sectional configuration of FIG. 9, these small pins 102 have a cylindrical portion 120 having an outer diameter substantially equal to the inner diameter of the fiber positioning hole 13 and a proximal end of the cylindrical portion 120 by gradually increasing the outer diameter. Frustoconical part 121 formed on the part side, and a cylindrical part 122 having a constant outer diameter formed on the base end part side
And a flange portion 12 having an outer diameter larger than the cylindrical portion 122.
4. These pins 101, 102
Is a hole 1 whose base end is provided in the first holding member 103.
40 and 131 are respectively inserted and accurately positioned and fixed.

Specifically, holes 104 and 131 provided at predetermined intervals so as to penetrate the first holding member 103 are provided.
Each pin 101, 102 is inserted from the tip to the end. The inner diameter of the hole 104 is substantially equal to the outer diameter of the cylindrical portion 112 of the pin 101, and the inner diameter of the hole 131 is
2 is almost equal to the outside diameter. Then, the crocodile portions respectively formed at the ends of the pins 101 and 102 are attached to the first holding member 10.
3 is pinched between the rear end surface 143 and the concave portion 144 formed on the front end surface of the second holding member 104, thereby positioning and fixing each pin.

Here, the forming pins 101 and 102 have a portion having a maximum outer diameter on the base end side, that is, a cylindrical portion 112,
The boundary portion with the end surface 114 of the first holding member 103
Preferably, it slightly protrudes from the holding surface position of 1. If the maximum outer diameter part is slightly projected, the guide hole 11 and the fiber positioning hole 1 of the ferrule to be molded are formed.
3 becomes the shape shown in FIG.
This is because 14 can be surely formed. The amount of protrusion is preferably 2 μm to 50 μm in consideration of errors during molding. If a margin of 2 μm is taken even in consideration of an actual mounting error or the like, the enlarged regions 12 and 14 can be reliably formed in the formed ferrule. 5
If it exceeds 0 μm, the cylindrical region becomes too long, which is not preferable for molding.

Cylindrical members 170 and 171 for receiving the tips of the pins 101 and 102 are slidably disposed so as to face the forming pin 101 and the small pin 102. A pair of first cylindrical bodies 170 that receive the tips of the molding pins 101
Is fixed between the third holding member 105 and the fourth holding member 106. The inner diameter of the first cylindrical body 170 is equal to the outer diameter of the cylindrical portion 110 of the forming pin 101,
The first cylindrical body 170 holds and positions the inserted cylindrical portion 110. Each first cylindrical body 170 itself is a cylinder 160 formed by combining semicircular grooves provided on opposing surfaces of the third holding member 105 and the fourth holding member 106.
It is accurately positioned and fixed inside.

Between the pair of first cylinders 170, four second cylinders 171 for receiving the distal ends of the small pins 102 are arranged, and these second cylinders 171 also have a base end on each side. It is sandwiched and fixed between the third holding member 105 and the fourth holding member 106. The second cylindrical body 171 is moved from the third holding member 105 and the fourth holding member 106 side to the first holding member 10.
3 and the second holding member 104 side, and the central part thereof penetrates the inside of the square part 172.

The inner diameter of the second cylindrical body 171 is
The second cylindrical body 171 holds and positions the inserted small pin 102. Like the first cylindrical body 171, each of the second cylindrical bodies 171 itself has a cylindrical shape formed by combining semicircular grooves provided on both surfaces of the third holding member 105 and the fourth holding member 106. Fifteen
1 is accurately positioned and fixed.

On the inner surfaces of the lower die 108 and the upper die 109, a concave portion 180 (the upper die 109 side is not shown) for forming the ferrule 1A is formed. The lower mold 108 has a projection 1 for forming the opening 14.
83 is formed in the recess 180. Further, rectangular cutouts 181 and 190 for inserting the rectangular part 172 and the cylindrical part 110 of the molding pin 101 are provided on the third holding member 105 and the fourth holding member 106 side of the lower die 108 and the upper die 109. Receiving semi-circular notches 182 and 191 are formed, respectively.

When the ferrule 1A is molded by the above-described mold, the lower mold 108 and the upper mold 109 are closed, and the molding pin 101, the small pin 102, and the second cylindrical body 171 are interposed therebetween. It is slid and placed in the molds 108 and 109. The tip of the forming pin 101 is inserted into the first cylindrical body 170 through the circular hole formed by the semicircular notches 182 and 191, and the tip of the small pin 102 is inserted into the second cylindrical body 171 and positioned. Is done. The rectangular portion 172 is introduced into the molds 108 and 109 via the rectangular cutouts 181 and 190, and the lower surface thereof is in surface contact with the upper surface of the convex portion 183.

Next, the molds 108 and 109 are filled with a molten resin, and then the resin is cooled and solidified. Column part 1
The pin hole 11 is formed by 10, and the enlarged area 12 is formed by the truncated cone 111. In addition, the fiber arrangement hole 13 is formed by the small pin 102, and the opening 14 is formed by the convex portion 183 and the square portion 172. Mold 108,
When the resin in 109 is solidified, the holding members 103 to 106
To the side, pull out the molding pin 101 and the like from the inside of the molds 108 and 109, and then,
Then, the upper mold 109 is opened, and the molded ferrule 1A is taken out.

When the forming pins 101 and 102 are pulled out, a so-called undercut portion is not generated.
It is only necessary to pull out the cylindrical portions 110 and 120 toward the truncated cone portions 111 and 121. For this reason, the ferrule 1A after molding
In order to form the enlarged regions 12 and 14, the slide core structure for forming the pin holes 11 and the fiber array holes 13 may be used. No need to provide.

According to the above-described manufacturing method, the enlarged regions 12 and 14 can be efficiently and accurately formed at the open ends of the pin hole 11 and the fiber positioning hole 13 of the manufactured ferrule 1A. According to the formed ferrule 1A, as described above, it is possible to suppress the loss and wear of the ferrule 1A and the optical fiber due to the detachment, have a good transmission characteristic, and to connect even if the detachment is repeatedly performed. It is possible to realize the optical connector C1 in which loss fluctuation hardly occurs.

Next, a second embodiment of the optical connector of the present invention will be described with reference to FIG.

The optical connector C2 shown in FIG. 10 is a so-called push-on type MPO connector. The pair of optical connectors C2 are pushed into the adapter A from opposite directions and connected. At this time, the ferrules 1B built in the distal end portion of the optical connector C2 correspond to each other in FIG.
As in the case of the ferrule 1A shown in FIG.
0 (not shown) and the pin hole 11.

Also in this case, by forming the enlarged regions 12 and 14, the ferrules 1B can be positioned smoothly while preventing the ferrules 1B from being lost or worn. In particular, in the case of a push-on type optical connector such as the optical connector C2, the guide pin 3 or the optical fiber end face and the joining end face cannot be visually observed when the guide pin 3 is inserted into the pin hole 11. However, there is a tendency that the ferrule 1B and the optical fiber are easily damaged or worn. For this reason,
As shown in FIG. 10, forming the enlarged regions 12 and 14 is a very effective means for preventing the ferrule 1B and the optical fiber from being damaged or worn in the push-on optical connector.

The optical connector of the present invention is not limited to the above-described embodiment. For example, the enlarged area may be formed by grinding after manufacturing the ferrule. Optical connectors are MT types other than the MPO type,
An MF type connector or the like may be used.

Here, the embodiment in which the enlarged area is provided also in the guide hole 11 has been described, but the enlarged area may be provided only in the fiber positioning hole. If a forming pin having no truncated cone portion 111 is used as the forming pin 101 in FIG. 8, it is easy to manufacture a ferrule having no enlarged region 12.

[0049]

As described above, according to the ferrule for an optical connector according to the present invention, the positioning hole is provided by increasing the opening diameter of the optical fiber positioning hole toward the connection end face on the connection end face side. In addition to preventing damage to the ferrule body such as chipped edges, it also effectively prevents damage to the fiber due to contact between the edge and the optical fiber, thus providing an optical connector with less splice loss even after repeated attachment and detachment. It is possible.

According to the method of manufacturing a ferrule for an optical connector according to the present invention, it is possible to preferably manufacture the ferrule for an optical connector according to the present invention having such features.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of an optical connector according to the present invention.

FIG. 2 is a cross-sectional view of the vicinity of a connection end surface of the ferrule for the optical connector of FIG. 1;

FIG. 3 is an enlarged sectional view of a fiber positioning hole of the optical connector of FIG. 1;

FIG. 4 is a diagram illustrating a problem of a conventional optical connector.

FIG. 5 is a diagram illustrating another problem of the conventional optical connector.

FIG. 6 is a diagram illustrating a comparison between a conventional optical connector (FIG. 6 (a)) and an optical connector according to the present invention (FIG. 6 (b)) in which foreign matter has entered a fiber positioning hole.

FIG. 7 is a diagram illustrating a modification of an enlarged area in a fiber positioning hole.

FIG. 8 is an exploded perspective view of a mold for manufacturing the optical connector of FIG.

9 is a sectional view taken along line IX-IX of FIG.

FIG. 10 is an exploded perspective view showing a second embodiment of the optical connector according to the present invention.

FIG. 11 is an exploded perspective view of a conventional optical connector.

FIG. 12 is a perspective view showing a connection state of the optical connector of FIG. 11;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ferrule, 2 ... Optical fiber core wire, 3 ... Guide pin, 4 ... Boot, 10 ... Joint end face, 11 ... Pin hole, 1
2, 14 ... enlarged area, 13 ... fiber positioning hole, 15
... Adhesive, 16 ... Opening, 20 ... Optical fiber, 21 ... Optical fiber end face, 101 ... Forming pin, 102 ... Small pin, 1
03 to 106: holding member, 108, 109: mold, 17
0, 171: cylindrical member.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshiaki Kakii 1-chome, Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa F-term in Sumitomo Electric Industries, Ltd. Yokohama Works 2H036 JA02 QA12 QA20 QA49

Claims (7)

[Claims] 1. A ferrule for an optical connector, which is used for positioning and fixing both optical fibers by an optical connector for performing optical connection by abutting end faces of optical fibers to be paired, wherein the ferrule body has a positioning member. A connection end face is formed on the end face side of the optical fiber to be fixed, and has a fiber positioning hole for positioning and fixing by inserting an optical fiber formed through the inside of the ferrule body from the connection end face into the inside, The ferrule for an optical connector, characterized in that the fiber positioning hole has an enlarged area near the connection end face, the inner diameter of which increases as the distance from the connection end face increases. 2. The ferrule main body is provided with a pair of guide holes for inserting guide pins for connecting optical connectors formed from the connection end face toward the inside of the main body with each other. 2. The ferrule for an optical connector according to claim 1, wherein the ferrule for an optical connector has an enlarged area near the connection end face, the inner diameter of which increases as the connection end face is closer. 3. The ferrule for an optical connector according to claim 1, wherein a wall surface of the enlarged region is formed as a conical surface or a curved surface protruding into the hole. 4. The ferrule for an optical connector according to claim 1, wherein an opening diameter of the fiber positioning hole at the connection end face is 0.13 mm or more and 0.25 mm or less. 5. An optical connector ferrule according to claim 1, wherein two pairs of optical fibers are paired, and said pair of optical fibers is positioned and fixed respectively. A pair of guide pins that are inserted into the respective guide holes of the ferrule for connection and connect both ferrules for optical connector. 6. The optical fiber according to claim 1, wherein each of the connection end faces of the optical fiber is disposed inside the ferrule main body with respect to the connection end face of the ferrule for an optical connector and at a position protruding into an enlarged area of the fiber positioning hole. The optical connector according to claim 5, wherein: 7. A method of manufacturing a ferrule for an optical connector used for positioning and fixing both optical fibers in an optical connector for performing optical connection by abutting end faces of a pair of optical fibers, comprising: a guide hole; A molding pin for forming a fiber positioning hole, wherein a predetermined number of molding pins having a cylindrical portion and an enlarged region formed on the base end side of the cylindrical portion and having an outer diameter gradually increased are formed by molding metal. A step of slidably arranging in the mold in the axial direction; a step of filling the mold with a resin; and Forming a ferrule main body having a hole and a fiber positioning hole.