JP3440408B2 - Ferrule for optical connector - Google Patents

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 which is attached to an end of an optical fiber when the optical fiber is connected by the optical connector.

[0002]

2. Description of the Related Art Conventionally, a ferrule for an optical connector is shown in FIG.
And sleeves 22 and 32 provided with insertion holes for inserting optical fibers along the central axis as shown in FIG.
And the flanged cylinders 21 and 31 integrally connected to the base ends of the sleeves 22 and 32. The optical connector ferrule of FIG. 5 was manufactured by press-fitting a stainless steel flanged cylinder 21 to the outside of the base end of a zirconia ferrule 22. In the ferrule for an optical connector shown in FIG. 6, a cylindrical body 31 with a flange made of stainless steel is fitted on the outer side of the base end of a sleeve 32 made of crystallized glass, and the overlapped flanges are bonded with an adhesive 33. Had been manufactured. The sleeve 32 made of crystallized glass breaks the sleeve 32 when the flanged cylindrical body 31 is press-fitted as in the case of FIG. 5, so that a method of bonding is adopted. To fix the flanged cylinders 21 and 31 and the sleeves 22 and 32 by press-fitting or bonding, it is necessary to integrate the flanged cylinders 21 and 31 and the sleeves 22 and 32 with a holding force equal to or higher than a standard value. That's why.

[0003]

In the method of manufacturing by press-fitting shown in FIG. 5, the inner diameter of a portion of the flanged cylinder 21 fitted to the base end of the sleeve 22 is made to correspond to the outer diameter of the sleeve 22. Since it was necessary to finish with a tolerance of about 10 μm, there was a problem that manufacturing was difficult and manufacturing cost increased. Further, in the method of manufacturing by bonding shown in FIG. 6, pay close attention to the amount and position of the adhesive applied so that the adhesive does not enter the optical fiber insertion hole formed along the central axis of the sleeve 32. It has to be paid, and there is a problem that the manufacturing is more difficult and the manufacturing cost is higher than the method by press fitting in FIG.

[0004] The present invention has been made in view of such problems, and can be easily manufactured and cost can be reduced.
Moreover, it is an object of the present invention to provide a ferrule for an optical connector having a structure capable of obtaining stable quality.

[0005]

SUMMARY OF THE INVENTION The ferrule for an optical connector of the present invention having the above-mentioned object has a structure in which a sleeve with a resin flange is formed on a sleeve by overmolding.

That is, according to the present invention, there is provided a sleeve provided with an insertion hole for inserting an optical fiber along a central axis, and a cylindrical body with a flange integrally connected to a base end of the sleeve. In the ferrule for an optical connector consisting of
The flanged tubular body is constituted by a resin molded article which is overmolded proximal end of the sleeve, and the flange portion of the flanged cylindrical member is overlapped on the base end outer sleeve, to the flange portion, A ferrule for an optical connector, comprising: a locking portion corresponding to a concave portion formed on an outer surface of a base end of a sleeve; and a thick portion corresponding to a small-diameter portion of the base end of the sleeve.

According to a second aspect of the present invention, there is provided a sleeve having an insertion hole through which an optical fiber is inserted along a central axis, and a flanged cylinder integrally connected to a base end of the sleeve. In the optical connector ferrule, the flanged tubular body is formed of a resin molded product overmolded at the base end of the sleeve, and the flange portion of the flanged tubular body extends outside the base end of the sleeve. wrapped and the light, characterized in that this flange portion includes a locking portion corresponding to the recessed portion formed on the proximal end outer surface of the sleeve, and a thick portion corresponding to the tapered tapered portion of the sleeve This is a ferrule for a connector.

Further, according to a third aspect of the present invention, there is provided a sleeve provided with an insertion hole for inserting an optical fiber along a central axis, and a flanged cylinder integrally connected to a base end of the sleeve. In the optical connector ferrule, the flanged tubular body is formed of a resin molded product overmolded at the base end of the sleeve, and the flange portion of the flanged tubular body extends outside the base end of the sleeve. wrapped and, to the flange portion includes a thick portion corresponding to the tapered tapered portion formed on the outer surface of the sleeve, and a locking portion corresponding to the annular ridge formed on the tapered surface of the tapered tapered portion This is a ferrule for an optical connector.

[0009]

According to the ferrule for an optical connector of the present invention, since the cylindrical body with the flange is formed integrally with the sleeve by overmolding the resin, a high-precision finishing work and an operation of applying an adhesive are required. It is possible to manufacture without.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 are a sectional view and a left side view of a ferrule for an optical connector according to a first embodiment. Reference numeral 1 denotes a resin-made flanged cylinder formed by injection molding .
The flange portion 1a of the flanged cylinder 1 is made of zirconia.
Over the base end of the sleeve 3
Overmolded. As the resin, what is called an engineering plastic can be used, and a polybutylene terephthalate resin containing glass is particularly preferable. A fiber lead 1c is formed in the flanged cylinder 1.
Is formed and communicates with the lead hole 3b of the insertion hole 3a for inserting an optical fiber provided along the central axis of the sleeve 3.
Have . As shown in FIG. 2, a flange 2 having a radial cutout 2a is integrally provided outside the flange portion 1a overlapping the sleeve 3.

The outer surface of the base end of the sleeve 3 is provided with a concave portion 4 extending in a predetermined angle range of the circumference and a small diameter portion 5 having an outer diameter smaller than that of the other portion (tip side). On the flange portion 1a of the body 1 overlapping the base end, a locking portion 6 is formed corresponding to the concave portion 4 and a thick portion 6a is formed corresponding to the small diameter portion 5. ing. Accordingly, the recessed portion 4 and the locking portion 6 are engaged with each other, and it is possible to prevent the flanged cylinder 1 and the sleeve 3 from rotating or coming off due to a difference in thermal contraction. ing. Further, by forming the thick portion 6a corresponding to the small diameter portion 5, necessary bending strength can be secured.

FIG. 3 is a sectional view of a ferrule for an optical connector according to a second embodiment. The same resin flange as in the previous embodiment
A cylindrical body 7 with a flange is provided . Flanged cylindrical flan
Di portion 7a is O to the proximal end of the crystallization glass sleeve 9
Overmolded with burlap
It is. The flange 8 similar to that of the above-described embodiment has a flange portion 7.
a .

On the outer surface of the base end of the sleeve 9, a recess 10 similar to the above is provided in advance, and a tapered portion 11 is formed. The flange 7 a of the flanged cylinder 7 corresponds to the recess 10. The locking portion 12 is formed and the tapered taper portion 1 is formed.
1, a thick portion 13 is formed. Therefore, the concave portion 10 and the locking portion 12 have a structure engaged with each other,
It is possible to prevent the flanged cylinder 7 and the sleeve 9 from rotating or coming off. In addition, by forming the thick portion 13 corresponding to the tapered portion 11, a necessary bending strength can be secured.

FIG. 4 is a sectional view of a ferrule for an optical connector according to a third embodiment. In the second embodiment, a plurality of annular ridges 13 are provided on the tapered surface of the tapered portion 11 formed at the base end of the sleeve 9 instead of the recessed portion 10 formed on the sleeve 9.
Is formed. It is formed by cutting an annular groove when cutting a tapered surface. It flanged tubular body 14 to the proximal end of such sleeve 9, the furan
It is overmolded so that the joints 14a overlap. Reference numeral 15 denotes a flange similar to that of the embodiment.

Accordingly, a thick portion 16 is formed on the flange portion 14a of the flanged cylindrical body 14 corresponding to the tapered tapered portion 11, so that a required bending strength is ensured and the annular protrusion 13 is formed. The locking portion 17 is formed on the tapered surface so that the sleeve 9 and the flanged cylinder 14 can be prevented from rotating or coming off.

Means for increasing the outer diameter of the fiber lead portion and the flange portion of the flanged cylindrical body to increase the wall thickness to enhance the bending strength can be considered. Cannot be fitted to the housings of the FC type optical connector and the SC type optical connector, and therefore cannot be adopted. Further, if the inner diameter of the fiber lead portion or the flange portion is reduced to increase the wall thickness, it becomes impossible to insert the coated core wire of the optical fiber of 0.9 mmφ, so that this cannot be adopted. Therefore, it is effective to form the thick portions 6a, 13 and 16 corresponding to the small diameter portion 5 and the tapered taper portion 11 as in the above-described embodiment, and to secure the bending strength.

[0018]

As described above, according to the present invention, a cylindrical body with a flange is integrally formed on a sleeve by overmolding, so that high-precision finishing and application of an adhesive are not required. So it can be easily manufactured and
A ferrule for an optical connector with stable quality can be provided.

[Brief description of the drawings]

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

FIG. 2 is a left side view of the ferrule for an optical connector according to the first embodiment.

FIG. 3 is a sectional view of a ferrule for an optical connector according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a ferrule for an optical connector according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional ferrule for an optical connector.

FIG. 6 is a sectional view of another conventional ferrule for an optical connector.

[Explanation of symbols]

1, 7, 14 Flanged cylinder 1a, 7a, 14a Flange 1c Fiber lead 2, 8, 15 Flange 2a Notch 3, 9 Sleeve 3a Insertion hole 3b Lead hole 4, 10 Recessed portion 5 Small diameter portion 6, 12 , 17 Locking portions 6a, 13, 16 Thick portion 11 Taper portion 13 Annular ridge

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryo Nagase Nippon Telegraph and Telephone Corporation 3-2-1-2 Nishishinjuku, Shinjuku-ku, Tokyo Within (72) Etsuji Sugita 1-3-1 Gotenyama, Musashino City, Tokyo No. NTT Advanced Technology Co., Ltd. (56) References JP-A-6-337326 (JP, A) JP-A-8-286080 (JP, A) JP-A-9-127368 (JP, A) JP-A-10-160970 (JP, A) JP-A 63-88807 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/36

Claims (3)

(57) [Claims] 1. A sleeve 3 having an insertion hole 3a for inserting an optical fiber along a central axis, and a flanged cylinder 1 integrally connected to a base end of the sleeve 3.
In the ferrule for an optical connector, the flanged cylinder 1 is formed of a resin molded product overmolded on the base end of the sleeve 3, and the flange 1 a of the flanged cylinder 1 is formed of a base of the sleeve 3. and overlapping the edge outwardly to the flange portion 1a, and the engaging portion 6 corresponding to the recessed portion 4 formed on the base end outer surface of the sleeve 3, the thick portion corresponding to the base end small-diameter portion 5 of the sleeve 3 6
a. A ferrule for an optical connector, comprising: a. 2. A light comprising a sleeve 9 provided with an insertion hole for inserting an optical fiber along a central axis, and a flanged cylinder 7 integrally connected to a base end of the sleeve 9. In the connector ferrule, the flanged cylinder 7 is formed of a resin molded product that is overmolded at the base end of the sleeve 9, and the flange portion 7 a of the flanged cylinder 7 extends over the base 9 outside the sleeve 9. wrapped and, to the flange portion 7a, it includes an engagement portion 12 corresponding to the recess 10 formed in the base end outer surface of the sleeve 9, and a thick portion 13 corresponding to the tapered tapered portion 11 of the sleeve 9 A ferrule for an optical connector. 3. A light comprising a sleeve 9 provided with an insertion hole for inserting an optical fiber along a central axis, and a flanged cylinder 14 integrally connected to a base end of the sleeve 9. in the ferrule connector, the flanged tubular body 14 is composed of a resin molded article which is overmolded proximal end of the sleeve 9, the flange portion 14a of the flanged tubular body 14 of the sleeve 9 groups
And overlapping the edge outwardly, the flange portion 14
a, a thick portion 16 corresponding to the tapered portion 11 formed on the outer surface of the sleeve 9 and a locking portion 17 corresponding to the annular ridge 13 formed on the tapered surface of the tapered portion 11. A ferrule for an optical connector, characterized in that: