JP3062532B2 - Optical fiber connector and method of manufacturing ferrule for optical fiber 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 known as an optical fiber connector component and a method of manufacturing the same.

[0002]

2. Description of the Related Art Heretofore, as this type of optical fiber connector, there is known an optical fiber connector having a ferrule formed by injection molding having a shape as shown in FIG.

The ferrule shown in FIG. 13 is composed of a ferrule main body 1, and the entire fiber insertion hole 2 of the ferrule main body 1 is formed to be elongated to have substantially the same diameter as the optical fiber from the time of injection molding. When an optical fiber is inserted into such a fiber insertion hole 2 from its entrance, positioning and fixing and centering of the optical fiber are performed over the entire fiber insertion hole 2, and the optical fiber is precisely held. You.

As a manufacturing process of the ferrule shown in FIG. 1, a series of processes 300 to 306 as shown in FIG. 14 are known.

In a process (molding) 300, as shown in FIG. 15A, the ferrule main body 1 (FIG. 13) is formed by an injection molding method or the like.
The ferrule material 1-1 serving as a basis for the reference (1) is molded.
This ferrule material 1-1 is formed in a columnar shape, and is provided so that a pilot hole 2-1 for inserting an optical fiber penetrates between both end surfaces thereof. The pilot hole 2-1 is the basis of the fiber insertion hole 2.

In the step (inner diameter polishing) 301, a plurality of ferrule materials 1-1,
All of the prepared holes 2-1 are polished at the same time as a bundle of 1-1... (See FIG. 15B).

For this inner diameter polishing, a setting wire 13 is passed through the prepared hole 2-1 to thereby set a plurality of ferrule materials 1-1 on the wire 13, and the plurality of ferrule materials 1-1 and 1-1 are set. Is loaded into a cylindrical body (sheath) 15, and an adhesive 16 such as solder or a rack is injected into the cylindrical body 15 to position and fix the set body 14. The operation of extracting the wire 13 and the like are sequentially performed. Next, a tapered polishing wire 12 (a wire having a larger diameter in the longitudinal direction and a constant diameter in the rear half portion) is inserted into the prepared hole 2-1 from the end face side of the cylindrical body 15. Thereafter, the cylindrical body 15 is rotated about the axis, and the loose abrasive particles 10 are sequentially attached and supplied to the tapered wire 12 before the ferrule material 1-1, and the tapered wire 12 is pulled out in the axial direction and wound on a reel (not shown). The prepared hole 2-1 is polished. The attachment and supply of the free abrasive grains 10 are performed by applying the liquid free abrasive grains 10 to the tapered wire 12 or immersing them.

[0008] That is, the inner diameter polishing is performed on the basis of the unprepared hole in which no processing is performed after molding.

After the polishing, the adhesive 16 is removed, and all the ferrule materials 1-1, 1-1,...

Process (outer diameter grinding [centerless method]) 30
In 2, from the viewpoint of efficiently removing the outer diameter margin of the ferrule material 1-1, the ferrule material 1-1 after the inner diameter polishing is set on a centerless support device or the like, and the outer diameter portion of the ferrule material 1-1 is set. Grind 1-1c without center (see FIG. 15C).

In step (end face grinding) 303, rough grinding is performed on both end faces 1-1a and 1-1b of the ferrule material 1-1 (see FIG. 15 (d)).

Process (outer diameter grinding [double center method]) 304
From the viewpoint of removing the eccentricity of the outer diameter of the ferrule material 1-1 and the prepared hole 2-1 and making them coaxial, FIG.
As shown in (e), the outer diameter portion 1 of the ferrule material 1-1.
-1c is ground. In such outer diameter grinding, the ferrule material 1-1 is supported at both centers. Both center supports 1-1a both sides of the end face of ferrule material 1-1,
The center jigs 6 and 7 are brought into contact with the prepared hole 2-1 from the 1-1b so that the ferrule material 1-1 is placed on both end faces 1-1.
a, 1-1b.

In step (outer diameter polishing) 305, the outer diameter portion 1-1c of the ferrule material 1-1 is polished to a desired roughness (see FIG. 15 (f)).

In step (end face processing) 306, processing such as making the end face of the ferrule material 1-1 a convex spherical surface is performed (FIG. 1).
5 (g)).

In the process (forming) 300, FIG.
As shown in FIG. 17A, when the ferrule material 1-1 is formed by injection, a reference step 17 is provided at the entrance 2-1b of the pilot hole 2-1. Outer diameter grinding [double center method]) Temporarily used as a reference for contact of the center jig 7 at the time of outer diameter grinding by the grindstone 12 of 304. Therefore, after the outer diameter grinding is completed, the reference step 1
7 from the viewpoint of preventing the optical fiber from being damaged by
V-cut on the prepared hole entrance 2-1b side (see FIG. 16 (b))
Or a rounding process (see FIG. 16 (c)) or the like, whereby the reference step 17 is scraped off, and the prepared hole entrance 2-1b, that is, the entrance of the fiber insertion hole 2 is formed into a smooth mortar shape without corners. Shall be finished.

On the other hand, the ferrule shown in FIG. 18 focuses on the point that the positioning and fixing (precision holding) of the optical fiber can be sufficiently performed only by the inner portion (one end side) 2a of the fiber insertion hole 2; This is configured from the viewpoint of reducing the finishing amount of the fiber insertion hole 2.

That is, in this ferrule, only the inner part (one end side) 2a of the fiber insertion hole 2 is provided with substantially the same diameter as the optical fiber strand from the time of injection molding, and other than this, the diameter is sufficiently larger than the diameter of the optical fiber strand. When an optical fiber is inserted into such a fiber insertion hole 2, the optical fiber is positioned and fixed only at the back (one end side), not at the entire fiber insertion hole 2. Centering and holding is performed.

[0018]

However, the above-mentioned conventional ferrule has the following problems.

The conventional ferrule shown in FIG. 13 has a structure in which the optical fiber is positioned and fixed over the entire fiber insertion hole 2, so that a finishing process for positioning and fixing the entire fiber insertion hole 2 is required. The processing amount,
The processing time is long, the manufacturing time of the ferrule is long, and it takes time to complete the manufacturing of the optical fiber connector.

Moreover, according to the conventional ferrule of FIG.
Since the fiber insertion hole 2 is elongated and long,
At the time of injection molding, the fiber insertion hole 2 is bent, and a step of correcting the bending is required separately. In addition, from the viewpoint of preventing the optical fiber strand from being damaged, the fiber insertion hole 2 is bent.
Since secondary processing such as V-cutting processing and R-mounting processing is required at the entrance of the optical fiber connector, the manufacturing process of the optical fiber connector also increases in this regard, and it takes a long time to complete the manufacturing and the manufacturing cost increases.

In the conventional ferrule shown in FIG.
As shown in (1), during the outer diameter grinding, the other end 2b of the fiber insertion hole 2 contacting the center jig 7 is formed by injection molding, so that the contour thereof has many irregularities, and the hole accuracy of the other end 2b of the fiber insertion hole is poor. Therefore, the contact between the center jig 7 and the other end 2b of the fiber insertion hole is unstable, and the accuracy of the outer diameter grinding (roundness of the ferrule outer diameter, coaxiality of the ferrule outer diameter and the fiber insertion hole, etc.) is reduced. As a result, the optical fiber connector with high accuracy cannot be obtained.

In order to avoid such inconveniences, it is conceivable to perform a so-called center hole processing for finishing the other end 2b of the fiber insertion hole to a predetermined dimensional accuracy before the outer diameter grinding. If such a center hole processing is newly added, the number of manufacturing steps of the optical fiber connector becomes extra, and it takes time to complete the manufacturing and the manufacturing cost increases.

Further, according to the conventional ferrule shown in FIG. 18, a step 18 exists on the inner side due to the difference in diameter between the inner side of the fiber insertion hole 2 and the other part. A nest (indentation) occurs around the step 18 due to a large change in the step area, and the positioning portion (the back part (one end 2a side) of the fiber insertion hole 2) ahead of the step 18 does not finish in a desired shape. In addition, the positioning and fixing of the optical fiber and the precision of centering and holding are poor. For this reason, a high-precision optical fiber connector cannot be obtained, and the reliability of optical communication is reduced. In addition, burrs are likely to be formed on the step, and the optical fiber is damaged by such burrs. Therefore, it is impossible to obtain a high-precision optical fiber connector and highly reliable optical communication in this regard.

The conventional ferrule manufacturing method as described above has the following problems.

In the conventional manufacturing method, as shown in FIG.
Since the positioning and fixing of -1 are performed by the adhesive 16, it is necessary to perform an operation of injecting and setting the adhesive 16 as a preparatory step for inner diameter polishing and an operation of removing the adhesive 16 as a subsequent step. Since it is necessary to rely on manual labor, time is required for the setup work, the entire manufacturing time of the ferrule is lengthened, it takes time to complete the manufacture of the optical fiber connector, and it is difficult to fully automate the manufacturing process.

Further, in the positioning and fixing with the adhesive 16 as described above, the set state of the ferrule material 1-1 is broken due to shrinkage of the adhesive 16 or the like, and the ferrule material 1-1 and the pilot hole 2-1 are connected to the cylindrical body 15. , The setting accuracy decreases, and the processing conditions for inner diameter polishing deteriorate. For this reason, desired processing accuracy cannot be obtained. Also, adhesive 1
In the case of No. 6, as described above, the set state is broken and the balance of the entire cylinder 15 is not good, so that the cylinder 15 cannot be rotated at a high speed, and the machining efficiency cannot be increased.

In the conventional manufacturing method, the eccentricity and parallelism of the prepared hole 2-1 and the outer diameter of the ferrule material are not at the desired accuracy. Since the inner hole is polished irrespective of the outer diameter of the ferrule material, the eccentricity of the prepared hole 2-1 with respect to the outer diameter of the ferrule material is determined by polishing the inner diameter regardless of the outer diameter of the ferrule material. The parallelism is not corrected, and the eccentric or inclined pilot hole 2-1 spreads as it is.
For this reason, not only the eccentricity and inclination due to the molding error in the process 300 but also the eccentricity and inclination of the spread of the prepared hole 2-1 must be anticipated in advance, and the extra diameter allowance of the ferrule material 1-1 must be provided extra. And spending time removing it,
The entire manufacturing time of the ferrule becomes long, and it takes time to complete the manufacturing of the optical fiber connector. In addition, the molding material of the ferrule material 1-1 is required accordingly, and the manufacturing cost of the optical fiber connector increases. Further, an extra step 304 for removing such inclination and eccentricity after inner diameter polishing is required.

According to the conventional manufacturing method, the outer diameter of the ferrule material 1-1 is large as described above, and the center jig is thin because the pilot hole 2-1 has a small diameter in the case of supporting both centers in step 304. In addition, since the processing efficiency is poor, a step of efficiently removing the outer diameter margin is required separately. In this sense, between the step 301 and the step 304, the centerless type outer diameter grinding which is excellent in machining efficiency is adopted as the step 302. However, in the case of the centerless type, the ability to reduce the eccentricity is inferior. Since the air cut for the eccentricity has to be set at the time of machining in step 304, step 3
The processing time of No. 04 cannot be significantly reduced, and the entire manufacturing time of the ferrule has not been reduced.

In order to correct the eccentricity of the pilot hole 2-1,
In step 302, wire centerless type outer diameter grinding may be applied instead of centerless type.
According to such a wire centerless system, it takes a long time for a setup operation such as an operation of setting the ferrule material 1-1 on a wire, and it is difficult to be unmanned, and an increase in manufacturing cost is inevitable.

In the conventional manufacturing method, in particular, if the pilot hole has a tapered shape like a nozzle as shown in FIG. 18, the ferrule material 1-1 as shown in FIG. Is set on the setting wire 13 at an angle, and the ferrule material 1 is
It is difficult to set -1 in parallel with high accuracy, and the deterioration of processing accuracy becomes more serious.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical fiber connector suitable for improving the accuracy of an optical fiber connector and simplifying a manufacturing process thereof. To provide ferrules suitable for improving the reliability of optical communication, simplifying the ferrule manufacturing process, shortening the manufacturing time, shortening the ferrule manufacturing time, fully automating the manufacturing process, improving the processing accuracy, etc. In particular, the present invention provides a ferrule manufacturing method suitable for reducing the parallelism and eccentricity of a pilot hole after polishing an inner diameter with respect to an outer diameter of a ferrule material for a tapered ferrule material (see FIG. 18 ) such as a nozzle. To provide a ferrule manufacturing method effective for improvement, to provide a ferrule manufacturing method suitable for reducing ferrule cost, shortening the manufacturing time, and the like. Lies in the fact.

[0032]

In order to achieve the above object, first, the present invention relates to an optical fiber connector comprising a ferrule main body for centering and holding an end of an optical fiber. In the ferrule body, one end side is formed of a holding hole having a hole diameter for holding the outer peripheral surface of the optical fiber, and the other end side is a fiber insertion hole communicating with the holding hole as a larger diameter portion having a larger diameter than the holding hole. A plurality of projections are formed on the inner wall on the other end side of the fiber insertion hole and serve as a reference for contacting a center jig used for outer diameter grinding of the ferrule main body.

Second, the present invention is characterized in that the surface shape of the projection is a curved surface.

[0034]

Third , the present invention uses a cylindrical ferrule material in which a pilot hole for inserting an optical fiber penetrates between the end faces, and roughly grinds the outer diameter of the ferrule material to obtain the outer diameter of the ferrule material. After removing the eccentricity of the hole, a plurality of eccentrically removed ferrule materials are brought into contact with the inside of the cylindrical holder and positioned and fixed in tandem, and then from the end face side of the cylindrical holder to the prepared hole of the eccentrically removed ferrule material. It is characterized in that the prepared hole is polished by inserting loose abrasive grains.

Fourth , the present invention uses a cylindrical ferrule material in which a pilot hole for inserting an optical fiber penetrates between the end faces, and a center jig is brought into contact with the pilot hole from both end faces of the ferrule material. With this, the center of the ferrule material is supported by the center jig from both end faces, and the outer diameter of this ferrule material is roughly ground to remove the eccentricity and inclination of the outer diameter of the ferrule material and the pilot hole. After polishing the prepared hole of this ferrule material based on the outer diameter of the material, the center jig is brought into contact with the prepared hole from both sides of the end surface of the ferrule material, and the ferrule material is supported by the center jig from both ends. The outer center finish grinding of the ferrule material is performed by supporting both centers.

[0037] Fifth, the present invention before the outer径粗grinding, is characterized in that performing the end face rough grinding of the pre ferrule material.

Sixth , the present invention provides an outer diameter finish grinding,
The present invention is characterized in that an end face finish grinding of a ferrule material is performed.

Seventh , the present invention is characterized in that the ferrule material is subjected to rough end grinding and finish grinding before or after finishing the outer diameter rough grinding.

According to the present invention, when the outer diameter of the ferrule body is ground, the center jig abuts not on the hole entrance having an irregular contour due to the injection molding, but on the abutment reference projection. Even if no processing is performed on the ferrule before the diameter grinding, the three-point contact of the center jig can be reliably obtained through the contact between the center jig and the projection.

According to the present invention, since the portion from the positioning portion to the entrance side of the fiber insertion hole smoothly spreads as a flared portion, it can be used for injection molding of the ferrule body.
The nest (indentation) and burrs are less likely to occur in the fiber insertion hole,
The optical fiber is not damaged by the burrs, the secondary processing for preventing such damage is omitted, and the optical fiber is inserted into the fiber insertion hole without performing the secondary processing. It becomes possible.

According to the present invention, the plurality of eccentrically removed ferrule materials are positioned and fixed on the basis of the outer diameter by contact with the cylindrical holder, and the pilot hole is ground using the ferrule material outer diameter as a processing reference.

According to the present invention, the eccentricity and inclination of the outer diameter of the ferrule material and the prepared hole are removed in advance by outer diameter grinding before the preparation of the prepared hole. For this reason, when providing the outer diameter allowance of the ferrule material, it is only necessary to consider only the eccentricity and inclination of the molding error generated at the stage of molding the ferrule material,
The outer diameter of the ferrule material can be minimized.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

The optical fiber connector has a ferrule as a means for centering and holding the end of the optical fiber.

The ferrule comprises a ferrule main body 1 having a shape as shown in FIG. 1, and the ferrule main body 1 is provided with a fiber insertion hole 2 for centering and holding a terminal portion of an optical fiber (not shown). Have been.

One end 2a of the fiber insertion hole 2 serves as a fine hole holding hole 200. Between the holding hole 200 and the other end 2b of the fiber insertion hole 2 has a larger diameter portion than the holding hole 200. 201.

The holding hole 200 is in close contact with the outer peripheral surface of the optical fiber and is configured to hold the outer peripheral surface of the optical fiber through this close contact. It is formed so as to smoothly spread from the holding hole 200 toward the other end 2 b of the fiber insertion hole 2.

That is, the holding hole 200 has a hole diameter for holding the outer peripheral surface of the optical fiber, and the enlarged diameter portion 201 is located on the other end 2 b side of the fiber insertion hole 2 from the boundary with the holding hole 200. The diameter is gradually widened toward the other end 2b of the insertion hole so that the diameter becomes maximum.

The other end 2b of the fiber insertion hole 2 is formed in a mortar shape, and has three protrusions 3 on its inner wall along the wall surface.
The projections 3, 3, 3 are all formed with a curved surface, and the tops 3a, 3a are provided.
a, 3a are provided so as to face the center axis side of the fiber insertion hole 2.

The protrusions 3, 3, 3 are used as a reference for contacting the center jig 7 when the outer diameter is ground after the ferrule main body 1 is injection-molded.
How 3 and 3 work will be described later.

In such a ferrule, when the end of the optical fiber is inserted from the other end 2b side of the fiber insertion hole 2, the optical fiber comes into close contact with the holding hole 200, and due to this close contact, the optical fiber is brought into contact. The optical fiber is centered and held and positioned and fixed, and the end of the optical fiber is precisely held.

In order to manufacture a ferrule having the above configuration, a mold 4 and a core pin 5 as shown in FIG. 2 are used.

The mold 4 is provided with a cavity 400 for forming the contour of the ferrule main body 1, while the core pin 5 is formed with an insertion hole shape portion 500 having substantially the same shape as the fiber insertion hole 2. .

When the ferrule body 1 is manufactured using the mold 4 and the core pin 5, the cavity 4 of the mold 4 is used.
After the core pin 5 is inserted into the core pin 5 and the insertion hole shape part 500 of the core pin 5 is positioned and fixed at a fixed position in the cavity 400, a ferrule material is injected and filled into the cavity 400, and the ferrule main body 1 is injection-molded.

Thereafter, as shown in FIG. 1, the ferrule body 1 is subjected to outer diameter grinding from the viewpoint of removing the eccentricity of the outer diameter of the ferrule body 1 and the eccentricity of the fiber insertion hole 2 and making them both coaxial.

At this time, the ferrule body 1 is supported at both centers. The two center supports support the ferrule main body 1 from both end surfaces 1a and 1b by a pair of left and right center jigs 6 and 7.

When the center jig is inserted into the fiber insertion hole 2 from both end surfaces 1a and 1b of the ferrule main body 1 to support both centers, the left center jig 6 is brought into contact with one end 2a of the fiber insertion hole 2. Contact, right center jig 7
Abuts on the protruding portions 3, 3, 3 on the other end 2b side of the fiber insertion hole 2.

That is, the right center jig 7 and the other end 2b side of the fiber insertion hole 2 come into contact with each other at three points around the circumference of the right center 7 via the convex portions 3,3,3.

After completion of the outer diameter grinding under the support of both centers as described above, if other processing such as polishing of the fiber insertion hole 2 is performed, a ferrule as a final product is obtained.

According to the ferrule of this embodiment, three protrusions 3, 3, 3 are provided on the inner wall of the other end of the fiber insertion hole 2, and these are brought into contact with the center jig 7 when the outer diameter of the ferrule main body 1 is ground. It is a reference. For this reason, when the outer diameter of the ferrule body 1 is ground, the protrusions 3, 3, 3 based on the abutment are not formed at the entrance of the hole having an uneven contour due to the injection molding.
Since the center jig 7 comes in contact with the center jig, the contact state of the center jig 7 is stable, and the accuracy of the outer diameter grinding (roundness of the ferrule outer diameter, coaxiality of the ferrule outer diameter and the fiber insertion hole, etc.) is improved. In addition, the precision of the ferrule can be improved, and a highly accurate optical fiber connector can be obtained.

Further, according to this ferrule, after the injection molding, the center jig 7 is brought into contact with the protruding portions 3, 3, 3 without performing any processing on the ferrule main body 1 before the outer diameter grinding. Since the three-point contact of the tool 7 is reliably obtained,
Before the outer diameter grinding, it is not necessary to finish the other end 2b of the fiber insertion hole 2 with a predetermined dimensional accuracy, the center hole processing for the finishing can be omitted, and the ferrule manufacturing process is reduced accordingly. The manufacturing process of the optical fiber connector can be simplified and the manufacturing cost can be reduced.

In particular, in this ferrule, since the projections 3, 3, 3 have a spherical shape, even if the projections 3, 3, 3 are left as they are, the projections 3, 3, 3 3, the optical fiber is not damaged, and the secondary processing for preventing the damage, for example, the conventional V-processing, R-forming, etc. can be omitted at all. And production costs can be reduced.

Furthermore, according to this ferrule, the center jig 7 contacts the other end 2b of the fiber insertion hole 2 at three points, and the contact resistance is small. And the processing efficiency can also be improved.

The number of points of contact between the center jig 7 and the other end 2b of the fiber insertion hole 2 is 3 due to the stability of the contact.
It is a three-point contact via the two protrusions 3,3,3. Therefore, if stable contact can be obtained, the number of the protrusions 3, 3, 3 is increased to three or more, and the center jig 7 and the other end 2b side of the fiber insertion hole 2 are contacted at three or more points. The number of the protruding portions can be changed as appropriate.

As shown in FIG. 3, the diameter-increased portion 201 is not a tapered hole.
Of the same diameter up to the other end 2b.

The shape of the projections 3, 3, 3 is
Any shape can be used as long as point contact in the circumferential direction can be obtained, and the shape is not limited to a curved shape. However,
It is necessary to have a shape that allows the core pin 5 to be pulled out during injection molding. Further, the protrusions 3, 3, 3 may be removed after the outer diameter grinding is completed.

FIG. 4 shows an embodiment of a ferrule according to the present invention. The ferrule shown in FIG. 4 comprises a ferrule main body 1 and a fiber for inserting an optical fiber (not shown) into the ferrule main body 1. An insertion hole 2 is provided.

The inner side 2a side of the fiber insertion hole 2 is at the position of the small hole.
As the placement part 202, the entrance 2b side of the fiber insertion hole 2
Is provided as a flared portion 203, and a positioning portion
202 is a light source similar to the holding hole 200 (see FIG. 1).
It comes into close contact with the outer peripheral surface of the fiber
The fiber strand is positioned and fixed.
Is from the positioning part 202 to the entrance 2b side of the fiber insertion hole 2.
It is formed so that it spreads smoothly toward
Is a curved spread having a large curvature.

That is, while the positioning portion 202 is formed to have substantially the same diameter as the optical fiber, the flared portion 203 gradually increases in diameter from the boundary with the positioning portion 202 toward the fiber insertion hole inlet 2b. The fiber insertion hole is provided such that the diameter becomes maximum on the inlet 2b side.

To manufacture such a ferrule, FIG.
The mold 4 and the core pin 5 shown in FIG.

The mold 4 is provided with a cavity 400 for forming the contour of the ferrule main body 1, while the core pin 5 is formed with an insertion hole shape portion 500 having substantially the same shape as the fiber insertion hole 2. .

In order to manufacture a ferrule using the mold 4 and the core pin 5 as described above, the cavity 400 of the mold 4 is required.
The core pin 5 is inserted into the
After the O is fixed at a fixed position in the cavity 400, the ferrule material is injected and filled into the cavity 400.

In the ferrule manufactured as described above, when the optical fiber is inserted from the entrance 2 b side of the fiber insertion hole 2, the optical fiber becomes the positioning portion 202.
In this case, the optical fiber is brought into close contact with the fiber insertion hole 2 so that the positioning and fixing of the optical fiber are performed.

In the ferrule of the present embodiment, the area from the positioning portion 202 to the entrance 2b side of the fiber insertion hole 2 is smoothly expanded as a flared portion 203. Therefore, when the ferrule main body 1 is subjected to injection molding or the like, burrs (indentations) and burrs are not easily generated in the fiber insertion hole 2, the positioning portion 202 can be finished in a desired shape, and the positioning and fixing accuracy of the optical fiber is fixed. Improves,
In addition, the optical fiber can be prevented from being damaged by burrs, so that the reliability of optical communication can be improved. Also,
The secondary processing (burr removal processing, V removal processing, R attachment processing, etc.) for preventing such damage can be omitted, and the optical fiber wire into the fiber insertion hole 2 can be omitted without performing the secondary processing. Since the ferrule can be inserted, the ferrule manufacturing process can be simplified, the manufacturing time can be reduced, and the manufacturing cost can be reduced.

According to the ferrule, only the inner side 2a of the fiber insertion hole 2 is formed as the positioning portion 202. Therefore, the finishing process for positioning and fixing is not required for the entire fiber insertion hole 2, but only for the positioning portion 202. Therefore, the finishing processing amount and processing time are reduced, and in this respect, the ferrule manufacturing time can be reduced, and the manufacturing process can be shortened. Cost can be reduced.

Further, according to the ferrule, only the positioning portion 202 of the fiber insertion hole 2 is formed as a small hole. For this reason, some, but not all, of the fiber insertion holes 2 are small holes, and the length of the small holes is short. Therefore, when the ferrule main body 1 is formed by injection or the like, the fiber insertion holes 2 are bent as much as possible. Decrease. Therefore, the process for correcting such a hole bending can be omitted, and the ferrule manufacturing process can be simplified. In this respect, the ferrule manufacturing time can be reduced and the manufacturing cost can be reduced.

It should be noted that the spread of the flared portion 203 is not curved but may be linear as shown in FIG. In this case, the flared portion 203 and the positioning portion 20
2 is preferably connected by a curved surface, that is, it is preferable to provide a curved surface portion 204 having no corner at the boundary between the flared portion 203 and the positioning portion 202, since the fiber is not caught or damaged when the fiber is inserted.

FIG. 7 shows an embodiment of a ferrule manufacturing method according to the present invention. The ferrule manufacturing method shown in FIG. 7 includes steps 100 to 104.

In step (forming) 100, a ferrule material 1-1 having a shape as shown in FIG. 8A is formed. Since the shape, molding method, and the like of the ferrule material 1-1 are the same as those in the related art, detailed description thereof will be omitted.

In the step (end face rough grinding) 101, after forming the ferrule material, both sides of the end face of the ferrule material 1-1 are 1-1.
The rough grinding is performed on a and 1-1b (see FIG. 8B).

Process (Outer diameter rough grinding [double center method]) 10
In FIG. 8, rough grinding is performed on the outer diameter portion 1-1c of the ferrule material 1-1 as shown in FIG. 8C, and the outer diameter of the ferrule material 1-1 and the eccentricity of the pilot hole 2-1 (ferrule material 1--1).
1) is removed, and the outer diameter of the ferrule material 1-1 and the prepared hole 2-1 are made coaxial.

In this rough outer diameter grinding, the ferrule material 1-1 is supported at both centers. Both centers are supported by bringing the centers 6 and 7 into contact with the prepared holes 2-1 from both sides 1-1a and 1-1b of the end face of the ferrule material 1-1. It shall be supported from the 1-1b side.

In the step (inner diameter polishing) 103, the prepared hole 2-1 is polished for the ferrule material 1-1 from which the eccentricity has been removed (see FIG. 8D).

In this inner diameter polishing, a cylindrical holder 9 having a shape as shown in FIG. 9 is used as a polishing jig. One end of the cylindrical holder 9 is opened as a material insertion port 900 and the other end of the cylindrical holder 9 is opened as a loose abrasive insertion port 901, and the inside of the body of the cylindrical holder 9 is formed as a material setting section 902. The inner diameter of the material setting section 902 is provided slightly larger in micro units than the outer diameter of the ferrule material 1-1 from which the eccentricity has been removed.

The eccentrically removed ferrule material 1 is inserted into the material setting portion 902 from the material insertion opening 900 side of the cylindrical holder 9.
Are inserted one by one, the ferrule materials 1-1, 1-1,... Come into contact with the cylindrical holder 9 and are positioned and fixed in tandem. 903 is pressed and fixed to the loose abrasive grain insertion port 901 side.

That is, in step 103, when the inner diameter is polished, a plurality of eccentrically removed ferrule materials 1
-1, 1-1... Are abutted in the cylindrical holder 9 and positioned and fixed in a column. Then, from the end face side of the cylindrical holder 9, the prepared holes 2-1, 2-1 ... of the ferrule materials 1-1, 1-1 ...
A tapered wire for polishing 12 and loose abrasive grains 10 are inserted into the gap. Thereby, all the pilot holes 2-1 2-1... Are ground at the same time with the outer diameter of the ferrule material 1-1 used as a processing reference. The insertion of the tapered wire 12 is performed through the loose abrasive insertion port 901.

In step 104 (end surface finish grinding),
Since the end face 1-1a is usually required to have a convex spherical surface finish, a process (pre-dome grinding) for making the end face 1-1a of the ferrule material 1-1 a convex spherical surface is performed (see FIG. 8 (f)).

In the ferrule manufacturing method according to the present embodiment, the ferrule material 1 with the eccentricity removed when polishing the pilot hole is used.
Are positioned and fixed by a simple one-touch operation only by contact with the cylindrical holder 9 without using an adhesive. For this reason, the use of an adhesive in the ferrule manufacturing process can be abolished, and a time-consuming and unmanned difficult set-up operation such as an adhesive injection setting operation and an adhesive operation can be omitted. This can reduce the time and is suitable for fully automating the manufacturing process.

In addition, according to this ferrule manufacturing method, the positioning and fixing of the ferrule materials 1-1, 1-1,... Because the set state of 1-1, 1-1 ... does not collapse, and the ferrule materials 1-1, 1-1 ... do not tilt and fall, the setting accuracy and the balance of the cylindrical holder 9 are good. Can be polished under good processing conditions, and processing such as parallelism and eccentricity of the prepared holes 2-1 2-1... With respect to the outer diameter of the ferrule material can be performed. The accuracy is improved, and the cylindrical holder 9 can be rotated at a high speed, and the processing efficiency is also improved.

In particular, this ferrule manufacturing method has a wireless system in which the ferrule materials 1-1, 1-1,... Are positioned and fixed only by directly abutting the ferrule materials 1-1, 1-1,. Therefore, it is possible to accurately set parallel positioning with respect to the cylindrical holder 9 with respect to the one having poor setting accuracy by the conventional positioning and fixing using a wire, for example, the one having the prepared hole 2-1 having a tapered nozzle shape. ,
Processing accuracy can be improved.

In this ferrule manufacturing method, the outer diameter of the ferrule material 1-1 and the eccentricity of the pilot hole 2-1 are removed by grinding the outer diameter in advance before polishing the pilot hole 2-1. It is not necessary to provide a step for removing eccentricity after polishing the pilot hole 2-1 as in the related art, and the process can be simplified.

If it is necessary to keep the eccentricity extremely small, it is also effective to perform outer diameter finish grinding after step 103 (inner diameter grinding) in order to correct the amount of eccentricity deterioration due to inner diameter grinding. For such outer diameter finish grinding, a double center support method similar to that in step 102 is appropriate.

The means for pressing and fixing the ferrule materials 1-1, 1-1... To the loose abrasive grain insertion port 901 side is not limited to the insertion and mounting of the screw 903 into the material insertion port 900, for example, as shown in FIG. A part of the ferrule material 1-1 may be projected outside from the material insertion port 900, and the pressing plate 10 may be screwed to the cylindrical holder 9 from the end of the ferrule material 1-1.
Although the cylindrical holder 9 shown in the figure is provided as a vertically split two-part type, the positioning and fixing can be performed by abutting the ferrule materials 1-1, 1-1.

The pressing and fixing means may be constituted not by screws but by, for example, claws 11 as shown in FIG. 11. In this case, the claws 11 are provided on the material insertion opening 900 side of the cylindrical holder 9. And ferrule material 1 by spring force
Can be pressed from the end face side toward the loose abrasive grain insertion port 901 side.

The cylindrical holder 9 may be provided with a plurality of vertically divided grooves like a collet, and may be opened and closed in the radial direction by utilizing the gap between the grooves. It can be in contact with the ferrule material to perform positioning and fixing.

FIG. 12 shows another embodiment of the ferrule manufacturing method according to the present invention. The ferrule manufacturing method shown in FIG. 12 includes steps 100a to 105a, and then details of the steps 100a to 105a. Will be described with reference to FIG.

In step (forming) 100a, a ferrule material 1-1 having a shape as shown in FIG. 8A is formed. Since the shape, molding method, and the like of the ferrule material 1-1 are the same as those in the related art, detailed description thereof will be omitted.

In the step (end face rough grinding) 101, after forming the ferrule material, both sides of the end face of the ferrule material 1-1 are 1-1.
The rough grinding is performed on a and 1-1b (see FIG. 8B). Since the rough grinding method is the same as the conventional one, a detailed description thereof will be omitted.

Process (outer diameter rough grinding [double center method]) 10
In 2a, rough grinding is performed on the outer diameter portion 1-1c of the ferrule material as shown in FIG. 8C. In such an outer diameter rough grinding, the ferrule material 1-1 is supported at both centers. Both center supports 1 on both sides of the end face of ferrule material 1-1
-1a and 1-1b are brought into contact with the centers 6 and 7 in the prepared hole 2-1.
a, 1-1b.

That is, in the step 102a, from the viewpoint of making the outer diameter of the ferrule material 1-1 and the prepared hole 2-1 coaxial, prior to the polishing of the prepared hole 2-1, the outer diameter supported by both centers is determined in advance. Rough grinding is performed, and the ferrule material 1-
The eccentricity and inclination of the outer diameter 1 and the pilot hole 2-1 are removed.

In the step (inner diameter polishing) 103a, FIG.
As shown in (d), the pilot hole 2-1 is polished for the ferrule material 1-1 which has been subjected to the outer diameter rough grinding. The inner diameter polishing is performed based on the outer diameter of the ferrule material 1-1, that is, while supporting the outer diameter portion 1-1c of the ferrule material 1-1.

Step (Outer diameter finish grinding [double center method]) 1
In 04a, as shown in FIG.
The outer diameter portion 1-1c of No. 1 is ground and finished. In such an outer diameter grinding finish, the ferrule material 1-1 is supported at both centers. Note that the support of both centers is the same as that in the step 102a, and a detailed description thereof will be omitted.

In step 105a (end surface finish grinding), a process (pre-dome grinding) or the like for making the end surface 1-1a of the ferrule material 1-1 a convex spherical surface is performed (see FIG. 8 (f)).

In the ferrule manufacturing method of the present embodiment, the eccentricity and inclination of the outer diameter of the ferrule material and the prepared hole 2-1 are removed by grinding the outer diameter before grinding the prepared hole 2-1. . For this reason, when providing the outer diameter allowance for the ferrule material 1-1, it is only necessary to consider only the eccentricity and inclination of the molding error generated in the molding step (process 100a) of the ferrule material 1-1. Of ferrule material 1-1
Therefore, the ferrule can be manufactured with a small amount of material at low cost.

According to this ferrule manufacturing method, the time required for the outer diameter grinding can be reduced because the margin for the outer diameter is reduced as described above, so that the ferrule manufacturing time can be shortened.

Further, in this ferrule manufacturing method, since all of the outer diameter grinding is performed by the double center method, it is difficult to perform unmanned operation such as wire setting work of a ferrule material in a wire centerless method, and it takes a long time. Since there is no setup work that is difficult to perform with high accuracy, it is suitable for automating the ferrule manufacturing process and improving the processing accuracy. Particularly, it is most suitable for obtaining a desired processing accuracy for the prepared hole of the nozzle shape.

The rough edge grinding in step 101a and the finish grinding in step 105a may be performed before the outer diameter rough grinding (step 102a) or after the outer diameter finish grinding (step 104a). it can.

[0109]

According to the present invention, at least three protruding portions are provided on the inner wall of the other end of the fiber insertion hole, and these are used as a reference for contacting the center during outer diameter grinding of the ferrule. For this reason, when the outer diameter of the ferrule is ground, the center jig abuts on the projection part of the abutment reference instead of the hole entrance having an irregular contour after the injection molding, so that the contact state of the center jig is stabilized, The precision of the outer diameter grinding is improved, and a high-precision optical fiber connector can be obtained.

According to the present invention, the three-point contact between the center jig and the protruding portion can be reliably obtained without any processing performed on the ferrule before the outer diameter grinding after the injection molding. In addition, it is not necessary to finish the other end of the fiber insertion hole to a predetermined dimensional accuracy in advance before the outer diameter grinding, and it is possible to omit the center hole processing for the finish, which reduces the number of ferrule manufacturing steps. The manufacturing process of the fiber connector can be simplified and the manufacturing cost can be reduced.

According to the present invention, the above-mentioned protruding portion may have a spherical shape. Therefore, even if the protruding portion is left as it is, the optical fiber is not damaged later by the protruding portion, and secondary processing for preventing scratching can be omitted. The manufacturing process can be simplified and the manufacturing cost can be reduced.

According to the present invention, the positioning portion
Between the fiber insertion hole and the fiber insertion hole
It is one that spreads smoothly. For this reason, the ferrule body
During the injection molding of the
Burrs and burrs are less likely to occur, and the positioning part is formed into a desired shape.
It can finish and fix the positioning of optical fiber
Optical fiber is damaged due to burrs
To improve the reliability of optical communications.
It is suitable for performing highly reliable optical communication. Also,
Secondary processing for preventing the damage can be omitted, and
The optical fiber element can be inserted into the fiber insertion hole without any processing.
Since the wire can be inserted, the ferrule manufacturing process
Simplification, shortening of manufacturing time, reduction of manufacturing cost, etc.
You.

According to the present invention, only the inner side of the fiber insertion hole is formed as the positioning portion. For this reason, the finishing process for positioning and fixing is not required for the entire fiber insertion hole, but only for the positioning part, so that the finishing processing amount and processing time are reduced, so that the ferrule manufacturing time and manufacturing cost are reduced. Can be achieved.

According to the present invention, only the positioning portion of the fiber insertion hole is formed as a small hole. For this reason, some but not all of the fiber insertion holes are small holes, and the length of the small holes is short, so that the bending of the fiber insertion holes becomes as small as possible during injection molding of the ferrule body. Therefore, a process for correcting such a hole bending can be omitted, and in this regard, the ferrule manufacturing process can be simplified, the manufacturing time can be reduced, and the manufacturing cost can be reduced.

Further, according to the present invention, when polishing a prepared hole, the eccentrically removed ferrule material is positioned and fixed by a simple one-touch operation only by contact with a cylindrical holder, not by an adhesive. is there. For this reason, the use of adhesives in the ferrule manufacturing process has been abolished, and this has eliminated the need for artificially time-consuming set-up work on the adhesive, thereby reducing ferrule manufacturing time and fully automating the manufacturing process. It is suitable for construction of a fully automatic manufacturing system aiming at labor saving and unmanned operation.

According to the present invention, the positioning and fixing of the ferrule material is performed by contact with the inside of the cylindrical holder. For this reason, the ferrule material setting state does not collapse in the cylindrical holder, and the ferrule material does not tilt and fall, and the setting accuracy and the cylindrical holder are well-balanced. In addition to being able to polish a prepared hole, the processing accuracy is improved, and the cylindrical holder can be rotated at a high speed, and the processing efficiency is also improved.

In the present invention, the ferrule material is positioned and fixed by a wireless method in which the ferrule material is directly brought into contact with the cylindrical holder. For this reason, even if the positioning and fixing using a wire as in the past is inferior in setting accuracy, for example, those having a pilot hole with a tapered nozzle shape, it can be set in parallel with the cylindrical holder with high accuracy, and the processing accuracy is improved. Can be achieved.

According to the present invention, the eccentricity of the outer diameter of the ferrule material and the prepared hole is previously removed by grinding the outer diameter before polishing the prepared hole. For this reason, first, it is not necessary to provide a step for removing eccentricity after polishing the prepared hole as in the prior art, and the step can be simplified in that such a step can be omitted. Secondly, in providing the outer diameter allowance for the ferrule material, it is only necessary to consider only the eccentricity and inclination of the molding error generated in the molding step of the ferrule material, so that the outer diameter allowance can be minimized. Accordingly, the molding material of the ferrule material and the time required for outer diameter grinding can be reduced, which is suitable for reducing the cost of this type of ferrule, shortening the manufacturing time, and the like.

According to the present invention, since all of the outer diameter grinding is performed by the double center method, it is difficult to perform unmanned operation such as wire setting work of a ferrule material in a wire centerless method, it takes a long time, and it is performed with high precision. There is no difficult setup work, and the ferrule manufacturing process can be automated and the processing accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view and a side view showing an embodiment of the present invention.

FIG. 2 is an explanatory view of a method of manufacturing the ferrule shown in FIG.

FIG. 3 is a cross-sectional view and a side view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing an embodiment of a ferrule according to the present invention.

FIG. 5 is an explanatory view of a method of manufacturing the ferrule shown in FIG.

FIG. 6 is a sectional view showing another embodiment of the ferrule according to the present invention.

FIG. 7 is an explanatory view showing one embodiment of a ferrule manufacturing method according to the present invention.

FIG. 8 is a detailed explanatory view of the manufacturing process shown in FIG. 7;

FIG. 9 is a sectional view of a cylindrical holder used in the ferrule manufacturing method shown in FIG. 7;

FIG. 10 is a sectional view showing another embodiment of the cylindrical holder.

FIG. 11 is a sectional view showing another embodiment of the cylindrical holder.

FIG. 12 is an explanatory view showing another embodiment of the ferrule manufacturing method according to the present invention.

FIG. 13 is a sectional view of a conventional ferrule.

FIG. 14 is an explanatory view showing a conventional ferrule manufacturing method.

FIG. 15 is a detailed explanatory diagram of the manufacturing process shown in FIG. 15;

FIG. 16 is an explanatory view showing a conventional ferrule manufacturing method.

FIG. 17 is an explanatory view showing a conventional ferrule manufacturing method.

FIG. 18 is a sectional view of another conventional ferrule.

FIG. 19 is an explanatory view showing a conventional ferrule manufacturing method.

FIG. 20 is an explanatory view showing a conventional ferrule manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrule main body 2 Fiber insertion hole 6, 7 Center jig 9 Cylindrical holder 11 Tapered wire 200 Holding hole 201 Large diameter part 202 Positioning part 203 Hem widening part 204 Curved surface part 1-1 Ferrule material 2-1 pilot hole

──────────────────────────────────────────────────の Continuing from the front page (31) Priority claim number Japanese Patent Application No. Hei 7-231725 (32) Priority date September 8, 1995 (September 9, 1995) (33) Priority claim country Japan (JP) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 6/36

Claims (7)

(57) [Claims] 1. An optical fiber connector comprising a ferrule main body for centering and holding an end portion of an optical fiber strand, wherein one end of the ferrule main body has a hole diameter for holding an outer peripheral surface of the optical fiber strand. A fiber insertion hole formed of a holding hole, the other end of which is connected to the holding hole as an enlarged diameter portion having a diameter larger than that of the holding hole; An optical fiber connector comprising a plurality of projecting portions forming a reference for contacting a center jig used for grinding. 2. The optical fiber connector according to claim 1, wherein a surface shape of the projection is a curved surface. 3. A pilot hole for inserting an optical fiber penetrates between end faces.
Using a cylindrical ferrule material made of The outer diameter of this ferrule material is roughly ground, and the ferrule element
After removing the eccentricity of the material outer diameter and pilot hole, Apply multiple ferrule materials with eccentricity removed into the cylindrical holder.
Contact and fix in position Then, remove the eccentricity from the end face of the cylindrical holder.
Free abrasive grains are inserted into the prepared hole of the rule material to polish the prepared hole.
To do Ferrule for optical fiber connector characterized by the following
Manufacturing method. 4. A pilot hole for inserting an optical fiber penetrates between end faces.
Using a cylindrical ferrule material made of Insert the center jig into the pilot hole from both sides of the end face of this ferrule material.
The ferrule material from both ends.
This ferrule element is supported by both centers supported by a metal jig.
Rough grinding of the outer diameter of the material,
Remove the mind and tilt, Then, based on the outer diameter of the ferrule material,
Polished pilot holes After Center jig abuts the prepared hole from both sides of ferrule material end face
This allows the ferrule material to be centered from both end faces.
The outer diameter of the ferrule material is supported by both centers supported by a jig
For optical fiber connectors characterized by finish grinding
Ferrule manufacturing method. 5. The method for manufacturing a ferrule for an optical fiber connector according to claim 4, wherein the end face rough grinding of the ferrule material is performed before the outer diameter rough grinding. 6. The method for producing a ferrule for an optical fiber connector according to claim 4, wherein the end face finish grinding of the ferrule material is performed after the outer diameter finish grinding. 7. The method for manufacturing a ferrule for an optical fiber connector according to claim 4, wherein the end face rough grinding and the end face finish grinding of the ferrule material are performed before the outer diameter rough grinding or after the outer diameter finish grinding. .