JPH07168054A - Optical connector ferrule - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an optical connector ferrule with excellent reliability. [Structure] An outside of a through-hole body 1 formed by communicating a small-diameter hole portion 2 for inserting an optical fiber portion whose coating is stripped and a large-diameter hole portion 3 for inserting an optical fiber core portion. In an optical connector ferrule in which a collar 4 is provided in the vicinity of the central portion, at least the tip of the small-diameter hole portion 2 of the through-hole body 1 extends from the collar 4
The outer periphery of the portion exceeding the above is formed by the hard member 5. [Effect] Since the hard member 5 is formed beyond the brim 4 of the through-hole body 1, the bending stress acting between the hard member 5 and the brim 4 is dispersed, and the hard member 5 does not drop from the brim 4. The reliability of the optical connector ferrule is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly reliable optical connector ferrule.

[0002]

2. Description of the Related Art An optical connector ferrule is for fixing the connecting end portion of an optical fiber to enhance its optical coupling property, and is required to have high dimensional accuracy. For example, the outer diameter tolerance is ±
0.5 μm or less, and the eccentricity between the center points of the inner diameter and the outer diameter is 0.5 μm or less. And the optical connector ferrule
As shown in FIG. 10B, the small-diameter hole portion 2 for inserting the optical fiber exposed by removing the coating of the optical fiber core wire and the large-diameter hole portion 3 for inserting the optical fiber core wire communicate with each other. A large-diameter collar 4 is formed in the vicinity of the central portion outside the provided through-hole body 1. The optical connector ferrule is this Tsuba 4
Then, it is attached to a connector housing (not shown). By the way, ceramics such as zirconia, which has high strength and high toughness and whose temperature and humidity do not affect the dimensional accuracy, are often used in the small-diameter hole portion 2 through which the optical fiber is inserted, and other parts of the optical connector ferrule are used. Resin and metal materials were used. Hard materials such as zirconia are difficult to process, so
Grinding was required to form a hole for inserting an m-diameter optical fiber, and the processing cost was high.

Under these circumstances, there has been proposed an optical connector ferrule shown in FIG. 10B in which the outer periphery of the small diameter hole portion 2 is formed of a hard member 5 and the inside is formed of resin. As a result, the inner diameter of the hard member 5 is increased, and a centerless grinder or the like can be used for drilling the optical fiber insertion hole, and the processing cost can be reduced. The optical connector ferrule shown in FIG. 10C is formed by corrugating the inner surface of the hard member 5 of the optical connector ferrule shown in FIG. 10B to enhance the adhesion of the resin inside.

These optical connector ferrules were manufactured by the press-fitting method. The press-fitting method is, as illustrated in FIG. 11, in which the insert 12 is arranged at the lower end of the fixed mold 8 and the cavity 13 is placed thereon.
And the cylindrical hard member 5 is placed inside the cavity 13.
Then, the movable mold 9 is placed on the fixed mold 8, the core pin 14 is inserted from above the movable mold 9, and the injection port of the movable mold 9 is inserted.
It is a method of manufacturing by injecting resin from 11. Hard member 5
The length of was a halfway length of the cavity 10 forming the collar in order to make the resin flow smooth.

[0005]

By the way, in the optical connector ferrule, the tip is inserted into the sleeve, and the tip of the mating optical connector ferrule is butted and connected in the sleeve. In addition, the hard member may fall off from the flange attached to the connector housing, which causes a problem in reliability.

[0006]

As a result of intensive studies in view of such a situation, the present invention has been found to cause the above-mentioned hard member to fall off when the tip of the optical connector ferrule is inserted into the sleeve. The inventors have found that bending stress is generated between the hard member and the brim, and have conducted further research to complete the present invention. That is, according to the present invention, the outside of the through-hole body formed by communicating the small diameter hole portion for inserting the optical fiber portion where the coating of the optical fiber core wire is removed and the large diameter hole portion for inserting the optical fiber core wire portion are communicated with each other. In the optical connector ferrule having a collar near the central portion, the outer periphery of at least the tip of the small-diameter hole portion of the through-hole body beyond the collar is formed of a hard member.

In the present invention, ceramics whose dimensional accuracy is not easily influenced by temperature and humidity are suitable for the material of the hard member. A resin or metal material is applied to portions other than the hard member forming the optical connector ferrule. It is preferable that the hard member integrally forms at least the outer circumference of the entire length of the through-hole body, because the hard member can be surely prevented from falling off. The small-diameter hole portion through which the optical fiber is inserted is formed by a hard member on the outer periphery and the inner side is formed by a resin or a metal material, so that the inner diameter of the hard member is increased, and as a result, the perforation of the optical fiber insertion hole of the hard member It can be done easily and the processing cost is reduced.

[0008]

In the present invention, the outer periphery of at least the tip of the small-diameter hole portion of the through-hole body beyond the collar is formed of a hard member, so that when the optical connector ferrule is inserted into the sleeve, the hard member and the collar are The bending stress applied between the two is dispersed in a wide range, and the hard member does not fall off the flange.

The present invention will be described in detail below with reference to examples. Embodiment 1 FIG. 1 is a vertical sectional view showing a first embodiment of the optical connector ferrule of the present invention. Reference numeral 1 denotes a through-hole body, which is composed of a small-diameter hole portion 2 through which an optical fiber is inserted and a large-diameter hole portion 3 through which an optical fiber core wire is inserted. A collar 4 is provided near the central portion outside the through-hole body 1. Optical connector ferrule is configured. The through-hole body 1 is integrally formed of a hard member 5, and the collar 4 is made of resin. Grooves 6 are continuously formed in the circumferential direction on the outer periphery where the brim 4 of the hard member 5 is located, and the dropout of the through-hole body 1 from the brim 4 is more reliably prevented.

Embodiment 2 FIG. 2 is a vertical sectional view showing a second embodiment of the ferrule of the present invention. In this ferrule, the collar 4 of the optical connector ferrule shown in FIG. 1 is formed of a metal material. Further, unlike the one shown in FIG. 1, there is no groove on the outer periphery where the collar 4 of the hard member 5 is located, and instead the step portion 7 is located inside the collar 4, and the rearward displacement of the hard member 5 does not occur. It is definitely prevented.

Third Embodiment FIG. 3 is a vertical sectional view showing a third embodiment of the ferrule of the present invention. In this ferrule, the outer periphery of the through-hole body 1 on the side of the small-diameter hole portion 2 side of the collar 4 and the entire rear end side of the collar 4 are made of hard member 5.
And the hard member 5 on the side of the hole 2 having a smaller diameter than the collar 4.
The inside of is formed of resin. A plurality of holes 15 penetrating in the radial direction are provided in the portion of the hard member 5 where the collar 4 is located,
Since the through hole 15 is filled with the resin, the hard member 5 is covered with the brim 4.
Is firmly fixed to. Since the inside of the hard member 5 closer to the small-diameter hole portion 2 than the collar 4 is made of resin, the inner diameter of the hard member 5 becomes large and the hard member 5 can be easily drilled.

Fourth Embodiment FIG. 4 is a vertical sectional view showing a fourth embodiment of the present invention. In this ferrule, the outer circumference of the through-hole body 1 is integrally formed by the hard member 5, and the groove 6 is continuously provided in the circumferential direction on the outer circumference where the collar 4 of the hard member 5 is located. The entire inner sides of the collar 4 and the hard member 5 are made of resin. Since the hard member 5 has a large inner diameter, it is easy to punch the hard member 5, and the continuous groove 6 in the circumferential direction formed on the outer circumference of the hard member 5 prevents the hard member 5 from falling off more reliably.

Embodiment 5 FIG. 5 is a vertical sectional view showing a fifth embodiment of the present invention. In this ferrule, the outer periphery of the through-hole body 1 on the side of the small-diameter hole portion 2 that sandwiches the collar 4 is formed of a hard member 5.
Protrudes to the rear end side of the collar 4. Tsuba 4 and hard member 5
The inside and the part of the large-diameter hole 3 side of the collar 4 excluding the hard member 5 are made of resin. The continuous groove 6 formed on the outer periphery of the hard member more reliably prevents the hard member 5 from falling off the collar 4. Since the inner diameter of the hard member 5 is large,
Perforation of the hard member 5 is easy.

A method of manufacturing the optical connector ferrule will be described below. FIG. 6 is a vertical cross-sectional explanatory view showing a mode in which the optical connector ferrule shown in FIG. 1 or 2 is manufactured by a press fitting method. A cavity 10 forming a collar is formed near the fixed die 8 of the movable die 9 of the press-fitting die composed of the fixed die 8 and the movable die 9. The cavity 10 communicates with the cavity 10 and the injection port 11 is formed.
Is provided. The insert 12 is arranged on the tip side of the fixed die 8 and the cavity 13 is arranged behind the insert 12, and the tip portion of the hard member 5 is fitted therein, and then the movable die 9 is brought closer to the fixed die 8 to move the hard member 5 After fitting the rear end portion into the movable mold 9 and bringing the fixed mold 8 and the movable mold 9 into close contact with each other, the injection port 11
A resin or metal material is injected from the above to form a brim in the central portion of the hard member 5.

FIG. 7 is a vertical cross-sectional explanatory view showing a mode in which the connector ferrule shown in FIG. 3 is manufactured by press-fitting a resin. A cavity 10 forming a collar is formed near the fixed die 8 of the movable die 9 of the press-fitting die composed of the fixed die 8 and the movable die 9, and an injection port 11 is provided in communication with the cavity 10. ing. Insert the insert 12 at the tip of the fixed mold 8 and then the cavity.
13 is arranged and the tip of the hard member 5 is fitted, then the movable mold 9 is brought close to the fixed mold 8 and the rear end of the hard member 5 is fitted into the movable mold 9, and then the core pin 14 is moved. The mold 9 is inserted from the rear side, then the fixed mold 8 and the movable mold 9 are brought into close contact with each other, and then the resin is injected from the injection port 11. The resin is supplied to the inside of the tip end side of the hard member 5 through the through hole 15 provided in the hard member 5, and then to the hollow portion 10 forming the collar 4.

FIG. 8 is an explanatory longitudinal sectional view showing a situation in which the connector ferrule shown in FIG. 4 is manufactured by press-fitting resin. The insert 12 and then the cavity 13 are arranged at the tip of the fixed mold 8 of the press-fitting mold composed of the fixed mold 8 and the movable mold 9, the hard member 5 is inserted therein, and the hard member 5 is further inserted.
A mold cavity 16 is arranged on the outer periphery of the rear part of the fixed mold 8
Then, the movable die 9 is closely attached to the core pin from the rear of the movable die 9.
Insert 14 into place, then move the movable mold 9 and fixed mold 8
The resin is injected from the injection port 11 between them.

FIG. 9 is a vertical cross-sectional explanatory view showing a situation in which the optical connector ferrule shown in FIG. 5 is manufactured by press fitting. It is the same as that shown in FIG. 8 except that the length of the hard member 5 is shortened and the shape of the irregular cavity 16 is changed accordingly. In order to inject the resin into the hard member 5, a through hole 15 was formed in the hard member 5 in the same manner as shown in FIG.

For manufacturing the cylindrical hard member, a method of extruding or injection-molding a ceramic powder such as zirconia or alumina or a superhard metal powder and subjecting it to a slight mechanical working is advantageous in mass productivity. Is.

[0019]

As described above, in the optical connector ferrule of the present invention, since the hard member is formed beyond the brim of the through-hole body, the bending stress acting between the hard member and the brim is dispersed, and the hard member is The reliability of the optical connector ferrule is improved without falling off from the collar.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of an optical connector ferrule of the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the optical connector ferrule of the present invention.

FIG. 3 is a vertical sectional view showing a third embodiment of the optical connector ferrule of the present invention.

FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the optical connector ferrule of the present invention.

FIG. 5 is a vertical sectional view showing a fifth embodiment of the ferrule of the present invention.

6 is a longitudinal cross-sectional explanatory view showing an aspect of a method for manufacturing the optical connector ferrule shown in FIGS. 1 and 2. FIG.

7 is a vertical cross-sectional explanatory view showing an aspect of a method for manufacturing the optical connector ferrule shown in FIG.

8 is a vertical cross-sectional explanatory view showing an aspect of a method for manufacturing the optical connector ferrule shown in FIG.

9 is a vertical cross-sectional explanatory view showing an aspect of a method for manufacturing the optical connector ferrule shown in FIG.

FIG. 10 is a vertical cross-sectional explanatory view of a conventional optical connector ferrule.

FIG. 11 is an explanatory longitudinal sectional view showing a method for manufacturing a conventional optical connector ferrule.

[Explanation of symbols]

 1 Through-hole body 2 Small-diameter hole part 3 Large-diameter hole part 4 Collar 5 Hard member 6 Groove 7 Stepped part 8 Fixed type 9 Movable type 10 Cavity forming cavity 11 Injection port 12 Nested 13 Cavity 14 Core pin 15 Through hole 16 Variant cavity

Claims (2)

[Claims] 1. An outer side of a through-hole body formed by connecting a small diameter hole portion for inserting an optical fiber portion of which an optical fiber core wire is stripped off and a large diameter hole portion for inserting the optical fiber core wire portion to communicate with each other. An optical connector ferrule in which a collar is provided in the vicinity of a central portion, wherein the outer periphery of at least the tip of the small-diameter hole portion of the through-hole body and beyond the collar is formed of a hard member. 2. The optical connector ferrule according to claim 1, wherein at least the outer periphery of the through-hole body is integrally formed of a hard member.