JP2000111758A - Production of ferrule for optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the degree of freedom in design by making it possible to arrange a flange for a spring integrally molded with a ferrule body made of a synthetic resin in an arbitrary position on the outer peripheral surface of a metallic pipe clad on the outer peripheral surface of the ferrule body and to make it possible to clad the metallic pipe to the ferrule body over a sufficient length without being restricted by the presence of the flange. SOLUTION: The ferrule for an optical connector has the metallic pipe 2 clad on the outer peripheral surface of the ferrule body 1 made of the synthetic resin in tight contact therewith, has the flange 3 for a spring rest made of the synthetic resin on the outer peripheral surface of the metallic pipe 2 and is formed by integrally molding the flange 3 for the spring rest made of the synthetic resin and the ferrule body 1 made of the synthetic resin via a connecting hole 4 bored through the peripheral wall of the metallic pipe 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ferrule used for centering and butting optical fibers in an optical connector.

[0002]

2. Description of the Related Art In Japanese Patent Publication No. 62-40684,
As shown in FIG. 4, a ferrule for an optical connector in which the outer peripheral surface of a ferrule body made of synthetic resin is covered with a metal pipe is shown. And at one opening end of the metal pipe, a spring receiving flange is formed integrally with the ferrule body,
The end of the pipe is inserted halfway through the base of the spring receiving flange.

The flange is indispensable as a spring receiving means of a connector built-in spring for abutting the ferrule end face to the mating ferrule end face.

[0004]

The ferrule having the structure covered by the metal pipe is effective for reinforcing the ferrule body made of synthetic resin and for maintaining the dimensional accuracy of the ferrule. The structure in which the spring receiving flange is integrally formed has a problem that the arrangement position of the flange is limited to a position beyond the opening end of the metal pipe, and the degree of freedom in design is reduced.

Depending on the installation position of the spring receiving flange, the length of the metal pipe is forcibly reduced. In addition, the front end of the ferrule projecting to one side (front) of the flange can be reinforced, while the other end (rear). The rear end of the ferrule that protrudes into the metal pipe cannot be reinforced, and has a problem that the intended purpose of the metal pipe is not properly exhibited.

Further, as shown in FIG. 8 of the above-mentioned prior art, since the flange is formed integrally with the ferrule main body at one open end of the metal pipe, this open end is set free in the flange forming cavity of the forming die. Therefore, there is a problem that the one end of the metal pipe cannot be stopped, and the metal pipe is moved in the axial direction by the molding pressure, so that it is difficult to manufacture the ferrule of the intended specification.

[0007]

SUMMARY OF THE INVENTION The present invention provides a ferrule for an optical connector and a method of manufacturing a ferrule which solves the above-mentioned problems while sufficiently achieving the object of reinforcing and accelerating the ferrule covered by a metal pipe. It is.

In short, the ferrule for an optical connector according to the present invention is a ferrule having a metal pipe closely attached to the outer peripheral surface of a ferrule body made of synthetic resin, and is in close contact with the outer peripheral surface of the metal pipe. It has a synthetic resin spring receiving flange.

The synthetic resin spring receiving flange and the synthetic resin ferrule main body are integrally formed through one or more connection holes penetrating through the peripheral wall of the metal pipe.

The metal pipe has a connecting hole extending through the peripheral wall of the pipe at a portion extending from the synthetic resin spring receiving flange, and a part of the synthetic resin forming the ferrule main body is in the connecting hole. Having an anchor structure filled in.

Further, the present invention provides a method for injecting a synthetic resin into a metal pipe through one or more holes penetrating through a peripheral wall of the metal pipe to form a ferrule main body in the pipe.

According to the present invention, the spring receiving flange integrally formed with the ferrule main body can be arranged at an arbitrary position on the outer peripheral surface of the metal pipe, and the design flexibility is greatly improved.

Further, the metal pipe is not restricted by the presence of the flange, and can be mounted on the ferrule main body over a sufficient length, and covers the peripheral surface of the ferrule main body extending in front of and behind the flange. The purpose of reinforcing the period and achieving the accuracy is fully demonstrated.

When the metal pipe is installed in the mold, both ends of the pipe are locked to the mold to prevent movement in the axial direction, and the installation position in the mold is securely held. Ferrules according to specifications can be molded properly. Therefore, it is possible to contribute to the above-mentioned improvement of the purpose of the metal pipe.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 to 4, a ferrule for an optical connector comprises a ferrule body 1 made of synthetic resin and a metal pipe 2 tightly mounted on the outer peripheral surface of the ferrule body 1. In addition, the metal pipe 2 has a spring receiving flange 3 made of a synthetic resin on the outer peripheral surface thereof.

A plurality of connection holes 4 or a plurality of connection holes 4 are provided in which the synthetic resin spring receiving flange 3 and the synthetic resin ferrule main body 1 penetrate through the peripheral wall of the metal pipe 2 at intervals in the circumferential direction. It is integrally formed via the connection hole 4.

As shown in FIGS. 1A, 1B, and 4, the metal pipe 2 has a coupling hole 5 extending from the synthetic resin spring receiving flange 3 through the peripheral wall of the pipe.

The connection hole 5 is provided in a metal pipe portion extending forward from the flange 3. The coupling hole 5 can also be provided in a metal pipe portion extending rearward from the flange 3. A part of the synthetic resin forming the ferrule body 1 is filled in the coupling hole 5.

The synthetic resin ferrule main body 1 and the synthetic resin spring receiving flange 3 are formed by filling a part of the synthetic resin 1 and 3 into a connection hole 4 provided in a peripheral wall of a metal pipe. The structure is such that the base material is connected to each other at a plurality of locations or a single location in the circumferential direction of the pipe 2.

As a result, the ferrule main body 1 and the spring receiving flange 3 on the outer peripheral surface and the inner peripheral surface of the metal pipe 2 can be integrally molded with the synthetic resin, and the spring receiving flange can be formed at an arbitrary position on the outer peripheral surface of the metal pipe 2. 3 can be arranged by the integral molding.

As shown in FIG. 5A, one or both of the connection hole 4 and the connection hole 5 are formed as through holes having a depth equal to the thickness of the metal pipe 2. Alternatively, as shown in FIG. 5B, the peripheral edge of the through hole is burred to form an annular protruding piece 6 to strengthen the connection with the ferrule main body 1. Similarly, the annular protrusion 6 may be formed by burring the periphery of the coupling hole 5.

FIGS. 2A, 2B, and 2C show a bottomed recess 7 in the outer peripheral surface of the metal pipe portion extending forward from the spring receiving flange 3 instead of the coupling hole 5 penetrating the metal pipe peripheral wall. While forming, projections 8 are formed on the inner peripheral surface of the pipe opposite to the recesses 7 by forming the recesses, and a plurality of the projections 8 are arranged in the circumferential direction of the metal pipe 2 in a balanced manner. It penetrates into the base material of the main body 1 to strengthen the connection.

Further, as shown in FIGS. 3A, 3B, and 3C, instead of the coupling hole 5 formed by the through hole and the projection 8 formed by the concave portion 7 having a bottom, the projection 8 extends forward from the spring receiving flange 3. While forming the annular bottomed recess 9 in the circumferential direction on the outer peripheral surface of the peripheral wall of the metal pipe portion to be formed, the annular rib 10 formed by the recess is formed on the inner peripheral surface of the pipe opposite to the concave 9. One or more annular ribs 10 are arranged at intervals in the axial direction of the metal pipe 2, and the annular ribs 10 protrude into the base material of the ferrule main body 1 to strengthen the connection.

As shown in FIG. 6, the metal pipe 2 extending to the front and rear of the flange 3 is embedded in the outer layer base material of the synthetic resin ferrule main body 1 within the thickness of the metal pipe 2. . In this case, the upper part of both ends of the metal pipe 2, that is, the upper part of the pipe thickness is embedded so as to protrude from the outer peripheral surface of the ferrule.

The ferrule main body 1 has an optical fiber insertion hole 11 penetrating on its axis, and the front end of the ferrule main body 1 in which the insertion hole 11 is opened projects from the end of the metal pipe 2.

As shown in FIGS. 6A and 6B, the front end protruding portion 12 is formed in an inclined shape in which the front end can be sworded, or as shown in FIG.
As shown in D, the annular corner around the end face is formed in an arc shape.

As shown in FIG. 11, in the ferrule having the above structure, the end face of the front end protruding portion 12 of the ferrule main body 1 is directly or indirectly abutted with the end face of the same main body 1 'of the mating ferrule, and the connection between optical fibers is established. Done. In order to obtain this butting force, the coil spring 14 built in the optical connector 13 is received by the flange 3 and the ferrule is urged forward.

Next, a method for molding the synthetic resin ferrule body 1 to the metal pipe 2 will be described with reference to FIGS.

According to this method, a synthetic resin is injected into the metal pipe 2 through a plurality of holes 4 or a single hole 4 penetrating through the peripheral wall of the metal pipe 2 at intervals in the circumferential direction. It is a method of molding.

More specifically, as shown in FIGS. 7A and 7B, the metal pipe 2 is installed so that the outer peripheral surface of the metal pipe 2 is in close contact with the inner peripheral surface of the ferrule main body forming cavity 16 of the molding die 15. The core 17 for forming the optical fiber insertion hole 11 is set on the axis.

Further, a forming cavity 18 of the spring receiving flange 3 is formed in the middle of the extending length of the metal pipe 2 by the forming die 15, that is, before the metal pipe 2 is installed, the ferrule main body forming cavity 16 is formed. A flange forming cavity 18 communicating with the peripheral surface of the cavity 16 is formed in the middle of the extension length.
Is opened in the flange forming cavity 18.

As shown in FIGS. 8A and 8B, a runner 19 communicating with the flange forming cavity 18 is provided in a mold, and the flange forming cavity 18 is passed through the runner 19.
The fluid synthetic resin 20 is press-fitted therein.

The fluid synthetic resin 20 is provided in the cavity 1 for forming a flange.
9A, B, 10A and 10B, the metal pipe 2 is injected into the metal pipe 2 (the cavity 16 for molding the ferrule main body) through the hole 4 to fill the cavity 16 and fill the cavity 16, as shown in FIGS. The forming flange 3 and the ferrule main body 1 are formed.

At the same time, the flowable synthetic resin 20 filling the inside of the pipe 2 overflows from both ends of the metal pipe 2 to both ends of the molding cavity 16 and forms portions of the ferrule main body 1 projecting from both ends of the metal pipe 2.

As shown in FIG. 7A, both end surfaces of the metal pipe 2 are engaged with the annular step portions 21 and 22 formed on the inner peripheral surface of the molding cavity 16 at the outer peripheral portions thereof, and the inner peripheral portion is formed by molding. Cavity 1
6 and the resin injection is performed. As a result, FIG.
As shown in A and B, the inner peripheral portion of the metal pipe 2 has a structure embedded in the ferrule main body 1.

The ferrule formed by the above-described manufacturing method has a metal pipe 2 closely attached to the outer peripheral surface of a ferrule main body 1 made of synthetic resin. A plurality of connection holes having a receiving flange 3, wherein the synthetic resin spring receiving flange 3 and the synthetic resin ferrule main body 1 are provided in the peripheral wall of the metal pipe 2 at circumferentially spaced intervals. 4 has a structure integrally formed.

Although the example in which the ferrule body 1 and the flange 3 are integrally formed has been described above, the present invention discloses the idea of forming the ferrule body 1 in the metal pipe 2.

The spring receiving flange 3 is recessed at intervals in the circumferential direction, and flange pieces 23 project radially. In this case, the gate of the runner 19 is opened at the top of the flange piece 23.

The molding die 15 is formed from a plurality of split dies, and it is needless to say that the metal pipe 2 and the core 17 can be installed and removed.

[0040]

According to the present invention, the spring flange integrally formed with the ferrule main body can be arranged at an arbitrary position on the outer peripheral surface of the metal pipe, so that the degree of freedom in design can be greatly improved.

The metal pipe is not restricted by the presence of the flange, but can be mounted on the ferrule main body over a sufficient length, and covers the peripheral surface of the ferrule main body extending forward and backward of the flange. The purpose of reinforcement of the period and the purpose of obtaining accuracy can be fully demonstrated.

When the metal pipe is installed in the mold, both ends of the pipe are locked to the mold to prevent movement in the axial direction, and the installation position in the mold is securely held. Ferrules according to specifications can be molded properly. Therefore, it is possible to contribute to the above-mentioned improvement of the purpose of the metal pipe.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a first example of a ferrule for an optical connector, and FIG.

2A is a perspective view showing a second example of a ferrule for an optical connector, FIG. 2B is a half-cut perspective view of the same, and FIG. 2C is an enlarged sectional view of a joint between a metal pipe and a ferrule main body.

3A is a perspective view showing a third example of a ferrule for an optical connector, FIG. 3B is a half-cut perspective view of the same, and FIG. 3C is an enlarged sectional view of a joint between a metal pipe and a ferrule main body.

FIG. 4 is a cross-sectional view of a ferrule in which a flange portion for a spring in the first to third examples is sectioned in a diametrical direction.

FIGS. 5A and 5B are cross-sectional views of a metal pipe illustrating examples of shapes of a connection hole and a coupling hole, respectively.

FIG. 6A is a longitudinal sectional view passing through the axis of the ferrule, and illustrates a case where both ends of a metal pipe are embedded;
3A is an enlarged view of portions a and b in A, and FIG.

7 to 10 are views for explaining a method of manufacturing a ferrule for an optical connector, FIG. 7A is a longitudinal sectional view showing a state in which a metal pipe and a core are installed in a molding die, and FIG. Area view.

8A is a longitudinal sectional view showing a state where the press-fitting of the resin is started in FIG. 7A, and FIG. 8B is a transverse sectional view thereof.

9A is a longitudinal sectional view showing an initial state in which the resin in FIG. 8A is injected into a metal pipe through a hole, and FIG. 9B is a transverse sectional view thereof.

10A is a longitudinal sectional view showing a state in which resin injection into a metal pipe through a hole in FIG. 9A is completed, and FIG. 10B is a transverse sectional view thereof.

FIG. 11 is a longitudinal sectional view showing a state where the ferrule is incorporated in an optical connector.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 synthetic resin ferrule main body 1 ′ mating ferrule main body 2 metal pipe 3 spring receiving flange 4 connecting hole 5 coupling hole 6 annular protrusion 7 bottomed recess 8 protrusion 9 bottomed annular recess 10 annular rib 11 optical fiber insertion Hole 12 Front end protruding part 13 Optical connector 14 Coil spring 15 Mold 16 Ferrule body molding cavity 17 Fiber insertion hole molding core 18 Flange molding cavity 19 Runner 20 Flowable synthetic resin 21 Annular step 22 Annular step 23 Flange Piece

[Procedure amendment]

[Submission date] August 27, 1999 (1999.8.2
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

The synthetic resin spring receiving flange and the synthetic resin ferrule main body are formed integrally with each other through a plurality of connection holes formed in the peripheral wall of the metal pipe at intervals in the circumferential direction. ing.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

The metal pipe has a plurality of connecting holes penetrating through the peripheral wall of the metal pipe at a portion extending from the synthetic resin spring receiving flange, and a part of the synthetic resin forming the ferrule main body is connected to the connecting pipe. It has an anchor structure filled in the hole.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

Further, according to the present invention, a spring receiving flange is formed on a peripheral wall of a metal pipe by a synthetic resin, and a synthetic resin is injected into the metal pipe through a plurality of holes formed through the peripheral wall at intervals in a circumferential direction. A method for forming a ferrule body in a pipe is provided.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

The synthetic resin spring receiving flange 3 and the synthetic resin ferrule main body 1 are connected to the peripheral wall of the metal pipe 2 through a plurality of connection holes 4 penetrating at intervals in the circumferential direction. It is integrally molded.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

As shown in FIGS. 1A, 1B, and 4, the metal pipe 2 has a plurality of connecting holes 5 penetrating the peripheral wall of the pipe at a portion extending from the synthetic resin spring receiving flange 3.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

The synthetic resin ferrule main body 1 and the synthetic resin spring receiving flange 3 are formed by filling a part of the synthetic resin 1 and 3 into a connection hole 4 provided in a peripheral wall of a metal pipe. It is a structure where the base material is connected to each other at a plurality of locations in the circumferential direction of the pipe 2.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

FIGS. 2A, 2B and 2C show a plurality of recesses with bottoms on the outer peripheral surface of the metal pipe portion extending forward from the spring receiving flange 3 instead of the coupling hole 5 penetrating the metal pipe peripheral wall. 7, a plurality of protrusions 8 are formed on the inner peripheral surface of the pipe opposite to the recesses 7 by forming the recesses, and a plurality of the protrusions 8 are arranged in a balanced manner in the circumferential direction of the metal pipe 2. The projection 8 is inserted into the base material of the ferrule body 1 to strengthen the connection.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

In this method, the metal pipe 2 is passed through a plurality of holes 4 penetrating through the peripheral wall of the metal pipe 2 at intervals in the circumferential direction.
Synthetic resin is injected into the ferrule body 1 inside the pipe 2
It is a method of molding.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Deleted ───────────────────────────────────────────── ────────

[Procedure amendment]

[Submission date] December 17, 1999 (1999.12.
17)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Manufacturing method of ferrule for optical connector

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ferrule used for centering and butting optical fibers in an optical connector.

[0002]

2. Description of the Related Art In Japanese Patent Publication No. 62-40684,
As shown in FIG. 4, a ferrule for an optical connector in which the outer peripheral surface of a ferrule body made of synthetic resin is covered with a metal pipe is shown. And at one opening end of the metal pipe, a spring receiving flange is formed integrally with the ferrule body,
The end of the pipe is inserted halfway through the base of the spring receiving flange.

The flange is indispensable as a spring receiving means of a connector built-in spring for abutting the ferrule end face to the mating ferrule end face.

[0004]

The ferrule having the structure covered by the metal pipe is effective for reinforcing the ferrule body made of synthetic resin and for maintaining the dimensional accuracy of the ferrule. The structure in which the spring receiving flange is integrally formed has a problem that the arrangement position of the flange is limited to a position beyond the opening end of the metal pipe, and the degree of freedom in design is reduced.

Depending on the installation position of the spring receiving flange, the length of the metal pipe is forcibly reduced. In addition, the front end of the ferrule projecting to one side (front) of the flange can be reinforced, while the other end (rear). The rear end of the ferrule that protrudes into the metal pipe cannot be reinforced, and has a problem that the intended purpose of the metal pipe is not properly exhibited.

Further, as shown in FIG. 8 of the above-mentioned prior art, since the flange is formed integrally with the ferrule main body at one open end of the metal pipe, this open end is set free in the flange forming cavity of the forming die. Therefore, there is a problem that the one end of the metal pipe cannot be stopped, and the metal pipe is moved in the axial direction by the molding pressure, so that it is difficult to manufacture the ferrule of the intended specification.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method of manufacturing a ferrule for an optical connector which solves the above-mentioned problems while sufficiently achieving the object of reinforcing and accelerating the ferrule covered with a metal pipe. .

In short, the ferrule for an optical connector according to the present invention is a ferrule having a metal pipe closely attached to the outer peripheral surface of a ferrule body made of synthetic resin, and is in close contact with the outer peripheral surface of the metal pipe. It has a synthetic resin spring receiving flange.

The synthetic resin spring receiving flange and the synthetic resin ferrule main body are integrally formed through a plurality of connection holes penetrating through the peripheral wall of the metal pipe.

According to the present invention, a synthetic resin is injected into the metal pipe through the plurality of holes which are formed in the peripheral wall of the metal pipe at intervals in the circumferential direction while forming a spring receiving flange on the peripheral wall of the metal pipe. A method for forming a ferrule body in the pipe is provided.

More specifically, the ferrule molding die is installed so that the outer peripheral surface of the metal pipe is in close contact with the inner peripheral surface of the ferrule main body molding cavity, and both end surfaces of the metal pipe are connected to the ferrule main body molding cavity. Engage with each of the annular steps formed on the inner peripheral surface and contact the outer peripheral surface of the metal pipe in the middle of the extending length of the metal pipe to form a molding cavity of a spring receiving flange by a molding die. The fluid synthetic resin in the flange forming cavity is injected into the metal pipe through a plurality of connection holes provided in the peripheral wall of the metal pipe at intervals in the circumferential direction while press-fitting the fluid synthetic resin into the molding cavity. Then, the spring receiving flange and the ferrule main body are integrally formed.

According to the present invention, the spring receiving flange integrally formed with the ferrule main body can be arranged at an arbitrary position on the outer peripheral surface of the metal pipe, and the design flexibility is greatly improved.

Further, the metal pipe is not restricted by the presence of the flange, and can be mounted on the ferrule main body over a sufficient length, and covers the peripheral surface of the ferrule main body extending in front of and behind the flange. The purpose of reinforcing the period and achieving the accuracy is fully demonstrated.

When the metal pipe is installed in the mold, both ends of the pipe are locked to the mold to prevent movement in the axial direction, and the installation position in the mold is securely held. Ferrules according to specifications can be molded properly. Therefore, it is possible to contribute to the above-mentioned improvement of the purpose of the metal pipe.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 to 4, a ferrule for an optical connector comprises a ferrule body 1 made of synthetic resin and a metal pipe 2 tightly mounted on the outer peripheral surface of the ferrule body 1. In addition, the metal pipe 2 has a spring receiving flange 3 made of a synthetic resin on the outer peripheral surface thereof.

The synthetic resin spring receiving flange 3 and the synthetic resin ferrule main body 1 are connected to the peripheral wall of the metal pipe 2 through a plurality of connection holes 4 penetrating at intervals in the circumferential direction. It is integrally molded.

As shown in FIGS. 1A, 1B, and 4, the metal pipe 2 has a plurality of connecting holes 5 penetrating the peripheral wall of the pipe at a portion extending from the synthetic resin spring receiving flange 3.

The connection hole 5 is provided in a metal pipe portion extending forward from the flange 3. The coupling hole 5 can also be provided in a metal pipe portion extending rearward from the flange 3. A part of the synthetic resin forming the ferrule body 1 is filled in the coupling hole 5.

The synthetic resin ferrule main body 1 and the synthetic resin spring receiving flange 3 are formed by filling a part of the synthetic resin 1 and 3 into a connection hole 4 provided in a peripheral wall of a metal pipe. It is a structure where the base material is connected to each other at a plurality of locations in the circumferential direction of the pipe 2.

As a result, the ferrule main body 1 and the spring receiving flange 3 on the outer peripheral surface and the inner peripheral surface of the metal pipe 2 can be integrally molded with the synthetic resin, and the spring receiving flange can be formed at an arbitrary position on the outer peripheral surface of the metal pipe 2. 3 can be arranged by the integral molding.

As shown in FIG. 5A, one or both of the connection hole 4 and the connection hole 5 are formed as through holes having a depth equal to the thickness of the metal pipe 2. Alternatively, as shown in FIG. 5B, the peripheral edge of the through hole is burred to form an annular protruding piece 6 to strengthen the connection with the ferrule main body 1. Similarly, the annular protrusion 6 may be formed by burring the periphery of the coupling hole 5.

FIGS. 2A, 2B, and 2C show a bottomed recess 7 in the outer peripheral surface of the metal pipe portion extending forward from the spring receiving flange 3 instead of the coupling hole 5 penetrating the metal pipe peripheral wall. While forming, a plurality of projections 8 formed by the recesses are formed on the inner peripheral surface of the pipe opposite to the recesses 7, and a plurality of the projections 8 are arranged in the circumferential direction of the metal pipe 2 in a balanced manner.
Into the base material of the ferrule body 1 to strengthen the connection.

Further, as shown in FIGS. 3A, 3B, and 3C, instead of the coupling hole 5 formed by the through hole and the projection 8 formed by the concave portion 7 having a bottom, the projection 8 extends forward from the spring receiving flange 3. While forming the annular bottomed recess 9 in the circumferential direction on the outer peripheral surface of the peripheral wall of the metal pipe portion to be formed, the annular rib 10 formed by the recess is formed on the inner peripheral surface of the pipe opposite to the concave 9. One or more annular ribs 10 are arranged at intervals in the axial direction of the metal pipe 2, and the annular ribs 10 protrude into the base material of the ferrule main body 1 to strengthen the connection.

As shown in FIG. 6, the metal pipe 2 extending to the front and rear of the flange 3 is embedded in the outer layer base material of the synthetic resin ferrule main body 1 within the thickness of the metal pipe 2. . In this case, the upper part of both ends of the metal pipe 2, that is, the upper part of the pipe thickness is embedded so as to protrude from the outer peripheral surface of the ferrule.

The ferrule main body 1 has an optical fiber insertion hole 11 penetrating on its axis, and the front end of the ferrule main body 1 in which the insertion hole 11 is opened projects from the end of the metal pipe 2.

As shown in FIGS. 6A and 6B, the front end protruding portion 12 is formed in an inclined shape in which the front end can be sworded, or as shown in FIG.
As shown in D, the annular corner around the end face is formed in an arc shape.

As shown in FIG. 11, in the ferrule having the above structure, the end face of the front end protruding portion 12 of the ferrule main body 1 is directly or indirectly abutted with the end face of the same main body 1 'of the mating ferrule, and the connection between optical fibers is established. Done. In order to obtain this butting force, the coil spring 14 built in the optical connector 13 is received by the flange 3 and the ferrule is urged forward.

Next, a method for molding the synthetic resin ferrule body 1 to the metal pipe 2 will be described with reference to FIGS.

According to this method, a synthetic resin is injected into the metal pipe 2 through a plurality of connection holes 4 penetrating through the peripheral wall of the metal pipe 2 at intervals in the circumferential direction, and the ferrule body 1 is formed in the pipe 2. It is.

More specifically, as shown in FIGS. 7A and 7B, the metal pipe 2 is installed so that the outer peripheral surface of the metal pipe 2 is in close contact with the inner peripheral surface of the ferrule main body forming cavity 16 of the molding die 15. The core 17 for forming the optical fiber insertion hole 11 is set on the axis.

Further, the forming cavity 18 of the spring receiving flange 3 is formed in contact with the outer peripheral surface of the metal pipe 2 in the middle of the extending length of the metal pipe 2 by the forming die 15, that is, before the metal pipe 2 is installed, the ferrule is formed. A flange forming cavity 18 communicating with the peripheral surface of the cavity 16 is formed in the middle of the extension length of the main body forming cavity 16, and the hole 4 is opened into the flange forming cavity 18.

As shown in FIGS. 8A and 8B, a runner 19 communicating with the flange forming cavity 18 is provided in a mold, and the flange forming cavity 18 is passed through the runner 19.
The fluid synthetic resin 20 is press-fitted therein.

The fluid synthetic resin 20 is provided in the cavity 1 for forming a flange.
9A, B, 10A and 10B, the metal pipe 2 is injected into the metal pipe 2 (the cavity 16 for molding the ferrule main body) through the hole 4 to fill the cavity 16 and fill the cavity 16, as shown in FIGS. The forming flange 3 and the ferrule main body 1 are formed.

At the same time, the flowable synthetic resin 20 filling the inside of the pipe 2 overflows from both ends of the metal pipe 2 to both ends of the molding cavity 16 and forms portions of the ferrule main body 1 projecting from both ends of the metal pipe 2.

As shown in FIG. 7A, both end surfaces of the metal pipe 2 are engaged with the annular step portions 21 and 22 formed on the inner peripheral surface of the molding cavity 16 at the outer peripheral portions thereof, and the inner peripheral portion is formed by molding. Cavity 1
6 and the resin injection is performed. As a result, FIG.
As shown in A and B, the inner peripheral portion of the metal pipe 2 has a structure embedded in the ferrule main body 1.

The ferrule formed by the above-described manufacturing method has a metal pipe 2 closely attached to the outer peripheral surface of a ferrule main body 1 made of synthetic resin. A plurality of connection holes having a receiving flange 3, wherein the synthetic resin spring receiving flange 3 and the synthetic resin ferrule main body 1 are provided in the peripheral wall of the metal pipe 2 at circumferentially spaced intervals. 4 has a structure integrally formed.

The spring receiving flange 3 is recessed at intervals in the circumferential direction, and flange pieces 23 project radially. In this case, the gate of the runner 19 is opened at the top of the flange piece 23.

The molding die 15 is formed from a plurality of split dies, and it is a matter of course that the metal pipe 2 and the core 17 can be installed and removed.

[0039]

According to the present invention, the spring flange integrally formed with the ferrule main body can be arranged at an arbitrary position on the outer peripheral surface of the metal pipe, so that the degree of freedom in design can be greatly improved.

The metal pipe is not restricted by the presence of the flange, but can be mounted on the ferrule main body for a sufficient length, and can cover the peripheral surface of the ferrule main body extending in front of and behind the flange. The purpose of reinforcement of the period and the purpose of obtaining accuracy can be fully demonstrated.

When the metal pipe is installed in the mold, both ends of the pipe are locked to the mold to prevent movement in the axial direction, and the installation position in the mold is securely held. The ferrule according to the specification can be properly molded. Therefore, it is possible to contribute to the above-mentioned improvement of the purpose of the metal pipe.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a first example of a ferrule for an optical connector, and FIG.

2A is a perspective view showing a second example of a ferrule for an optical connector, FIG. 2B is a half-cut perspective view of the same, and FIG. 2C is an enlarged sectional view of a joint between a metal pipe and a ferrule main body.

3A is a perspective view showing a third example of a ferrule for an optical connector, FIG. 3B is a half-cut perspective view of the same, and FIG. 3C is an enlarged sectional view of a joint between a metal pipe and a ferrule main body.

FIG. 4 is a cross-sectional view of a ferrule in which a flange portion for a spring in the first to third examples is sectioned in a diametrical direction.

FIGS. 5A and 5B are cross-sectional views of a metal pipe illustrating examples of shapes of a connection hole and a coupling hole, respectively.

FIG. 6A is a longitudinal sectional view passing through the axis of the ferrule, and illustrates a case where both ends of a metal pipe are embedded;
3A is an enlarged view of portions a and b in A, and FIG.

7 to 10 are views for explaining a method of manufacturing a ferrule for an optical connector, FIG. 7A is a longitudinal sectional view showing a state in which a metal pipe and a core are installed in a molding die, and FIG. Area view.

8A is a longitudinal sectional view showing a state where the press-fitting of the resin is started in FIG. 7A, and FIG. 8B is a transverse sectional view thereof.

9A is a longitudinal sectional view showing an initial state in which the resin in FIG. 8A is injected into a metal pipe through a hole, and FIG. 9B is a transverse sectional view thereof.

10A is a longitudinal sectional view showing a state in which resin injection into a metal pipe through a hole in FIG. 9A is completed, and FIG. 10B is a transverse sectional view thereof.

FIG. 11 is a longitudinal sectional view showing a state where the ferrule is incorporated in an optical connector.

[Description of Signs] 1 Synthetic resin ferrule main body 1 'Mating ferrule main body 2 Metal pipe 3 Spring receiving flange 4 Connecting hole 5 Coupling hole 6 Annular protruding piece 7 Bottomed recess 8 Projection 9 Bottomed annular recess 10 Annular rib 11 Optical fiber insertion hole 12 Front end protrusion 13 Optical connector 14 Coil spring 15 Mold 16 Ferrule body molding cavity 17 Fiber insertion hole molding core 18 Flange molding cavity 19 Runner 20 Flowable synthetic resin 21 Annular step 22 Annular step 23 Flange piece

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kiyoshi Ishii 3-28-7 Nakamagome, Ota-ku, Tokyo Yamaichi Electric Co., Ltd. F-term (reference) 2H036 QA12 QA18 QA19 QA20

Claims (3)

[Claims] 1. A synthetic resin ferrule body having a metal pipe closely attached to an outer peripheral surface thereof, a synthetic resin spring receiving flange provided on an outer peripheral surface of the metal pipe, and A ferrule for an optical connector, wherein a spring receiving flange made of stainless steel and a ferrule body made of the synthetic resin are integrally formed through a connection hole penetrating through a peripheral wall of the metal pipe. The metal pipe has a connecting hole extending through the peripheral wall of the pipe at a portion extending from the synthetic resin spring receiving flange, and a part of the synthetic resin forming the ferrule main body is formed in the connecting hole. The ferrule for an optical connector according to claim 1, wherein the ferrule is filled in the inside. 3. A method for manufacturing a ferrule, wherein a synthetic resin is injected into a metal pipe through a hole formed through a peripheral wall of the metal pipe, and a ferrule body is formed in the pipe.