JPH09304652A - Optical connector plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector plug which is compact and can secure water-proof effect and an excellent optical connection state. SOLUTION: This plug 1 is equipped with a connector housing 4, a ferrule 3, an inner boot 5, and a cap body 6. The ferrule 3 is connected to an end part of an optical fiber 2. The connector housing 4 has a storage hole part which holds the ferrule 3 inserted into one side so that it is stopped from coming out to the other side. The inner boot 5 has an expansible deformable bellows part 5 and a connection part 5b which is connected to an end part of the ferrule 3. The cap body 6 is mounted compressing the inner boot 5 and closing the opening of the connector housing 1. The bellows part 5a is so formed that when the cap body 6 is mounted, the compressed bellows part 5a comes into contact with the outer peripheral surface of the optical fiber 2 and the inner peripheral surface of the storage hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector plug arranged at a relay point of an optical signal transmission line using an optical fiber.

[0002]

2. Description of the Related Art Generally, an optical signal transmission line using an optical fiber is laid by optically connecting it with an optical connector plug or the like at an appropriate distance. There is a part that needs a waterproof structure to protect it from the above.

Conventionally, as a waterproof structure for this type of optical connector plug, as disclosed in Japanese Utility Model Publication No. 7-25766, a structure in which the entire connector plug is covered with waterproof boots, and the actual open type Sho 63-180806. As disclosed in the publication, a structure in which a connector plug is attached to an end of an optical fiber, and an expandable cap is integrally provided to surround and cover the outer periphery of the end of the optical fiber is disclosed. is there.

[0004]

However, in the structure in which the entire connector plug is covered with the waterproof boot as described above, the waterproof boot becomes large, so that the fitting portion with the device side becomes large, and thus it is used. There are restrictions on the devices that can be used,
In particular, it has a drawback that it cannot be applied to small devices.

Further, in the structure in which the expandable cap is integrally provided with the connector plug, it is necessary to use an elastic material as the material for making the cap expandable, and therefore the optical fiber is used. Since the material of the connector plug itself supporting the end of the connector is also an elastic material, it is inferior in rigidity against external force such as bending and there is a possibility that the optical connection state between the optical fibers connected to each other may be hindered. It was

On the other hand, in order to ensure a good optical connection between the optical fibers connected to each other, a ferrule connected to the end of the optical fiber is used as disclosed in Japanese Utility Model Laid-Open No. 5-21214. There is also a structure in which a coil spring is mounted so as to always urge elastically in the connecting direction.

In view of the above problems, an object of the present invention is to provide an optical connector plug which is compact and which can secure a good waterproof effect and a good optical connection state.

[0008]

The technical means for achieving the above object is to connect an end portion of an optical fiber in an optical connector plug arranged in an optical signal transmission line using the optical fiber. A connector housing having a housing hole portion for inserting the ferrule from one side and retaining and holding the ferrule on the other side, and an elastically deformable telescopic portion fitted into the optical fiber.
Inner boot made of an elastic material having a connecting portion connected to the one end of the ferrule and an optical fiber, and the inner boot is compressed to the ferrule side to accommodate the connector housing. A cap body mounted in a state in which the opening on the one side of the hole portion is closed, wherein the elastic portion of the inner boot is a compressed elastic member when the cap body is attached to the connector housing. It is formed so as to be in close contact with the outer peripheral surface of the optical fiber and the inner peripheral surface of the accommodation hole.

Further, the expandable part may be formed in a bellows shape.

Further, the ferrule may be made of a metal material, and the connecting portion of the inner boot may be inserted into the end of the ferrule, and the ferrule, the connecting portion and the optical fiber may be caulked.

The inner diameter of the connecting portion of the inner boot may be smaller than the outer diameter of the end portion of the ferrule on one side, and the end portion of the ferrule may be press-fit into the connecting portion. .

Further, the ferrule may have a structure in which a peripheral groove is formed on the outer periphery of the end on one side, and a projection portion, which is locked in the peripheral groove, is provided on the inner peripheral surface of the connecting portion of the inner boot. Good.

Further, the end portion of the inner boot side of the cap body is inserted into the end portion of the inner boot, and the end portion of the inner boot is attached to the inner peripheral surface side of the accommodating hole portion when mounted on the connector housing. The structure may be such that a crimping cylinder portion for crimping is provided in a protruding manner.

Further, a structure may be formed in which an outer peripheral surface of the crimping cylinder portion of the cap body is formed with an engaging groove portion for preventing the end edge portion of the inner boot from being withdrawn.

Further, the connector housing is provided with an accommodating hole portion for inserting the ferrules respectively connected to the end portions of the plurality of optical fibers from one side and retaining and holding the ferrules to the other side. A plurality of optical fibers are inserted into the cap body, each of which includes a stretchable and deformable stretchable portion that is fitted into the fiber and a connecting portion that is connected to the one end of each ferrule. It is also possible to adopt a structure provided with a through hole.

Further, the connector housing, the inner boot, the cap body, and the ferrule may each be made of an insulating material.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 6, an optical connector plug 1 is connected to an end portion of an optical fiber 2. Connector housing 4 for accommodating and holding the ferrule 3, inner boot 5 accommodated in the connector housing 4, and opening 4a on one side of the connector housing 4.
And a cap body 6 that is mounted so as to close the.

The connector housing 4 is formed of an insulating synthetic resin or the like, and its outer shape is formed in a rectangular tubular shape. Then, a circular accommodating hole portion 4b communicating with the opening 4a on the one side and toward the other side.
Are formed.

Further, the other end portion of the accommodation hole portion 4b is provided with a projecting wall portion 4c which is formed so as to project toward the inner peripheral surface side, and the central portion thereof is constituted as an insertion hole 4d.

The outer shape of the other end of the connector housing 4 is formed in a smaller rectangular shape through the step 4e.

Further, a pair of locking holes 4f are formed at one end of the connector housing 4 so as to correspond to the position of the opening 4a and are vertically opposed to each other.

The cap body 6 is formed in a rectangular block shape corresponding to the opening 4a by a synthetic resin having an insulating property, and the opening 4 of the connector housing 4 is formed.
When it is mounted in a state in which a is closed, locking portions 6a that are locked in the locking holes 4f are formed so as to project vertically. Further, an insertion hole 6b through which the optical fiber 2 is inserted is formed in the central portion of the cap body 6.

The ferrule 3 is made of a metal material, and has a cylindrical base portion 3a, and an annular brim portion 3b that is formed so as to project radially outward on the outer periphery of the axially intermediate portion of the base portion 3a.
The base portion 3a includes a tip portion 3c protruding from one end side with a smaller outer diameter.

The optical fiber 2 is composed of a core wire portion 2a serving as a core and a coating portion 2b covering the outer periphery thereof,
The tip portion 3c is provided with a core wire insertion hole 3d having an inner diameter substantially the same as the outer diameter of the core wire portion 2a.

Further, the base portion 3a is provided with a fiber insertion hole 3e having an outer diameter of the covering portion 2b, that is, an inner diameter substantially the same as the outer diameter of the optical fiber 2, and the open end side of the base portion 3a has the above-mentioned structure. The end of the inner boot 5 is inserted,
A boot insertion hole 3f having a larger diameter is provided.

The inner boot 5 is made of an elastic material such as rubber, for example, silicone elastomer,
A bellows portion 5a formed in a bellows shape as a stretchable and deformable stretchable portion fitted over the optical fiber 2, and a boot insertion hole 3f provided so as to project from one end of the bellows portion 5a.
And a cylindrical connecting portion 5b to be inserted into the.

The outer diameter of the large diameter portion on the outer peripheral surface of the bellows portion 5a is the same as the accommodating hole portion 4 of the connector housing 4.
The inner diameter of the small diameter portion on the inner peripheral surface of the bellows portion 5a is formed to be substantially the same as or slightly larger than the outer diameter of the optical fiber 2. ing.

Then, as shown in FIG. 1, the optical fiber 2 is covered with the covering portion 2b for a predetermined length and the core portion 2a is exposed to expose the core 2a. The boots 5 are sequentially fitted and mounted, and the end of the optical fiber 2 is inserted into the ferrule 3.

At this time, as shown in FIG. 3, the exposed core wire portion 2a is inserted into the core wire insertion hole 3d of the ferrule 3, and the covering portion 2b is inserted into the fiber insertion hole 3e.
Further, the connecting portion 5b of the inner boot 5 has the boot insertion hole 3
It is inserted in f.

Then, in the above-mentioned inserted state, as shown in FIG. 4, the outer peripheral surface of the ferrule 3 is caulked at the two positions corresponding to the inserting position of the connecting portion 5b and the inserting position of the covering portion 2b. Then, the ferrule 3, the optical fiber 2 and the inner boot 5 are connected to each other in a retaining state.

Then, in this state, as shown in FIG.
The connector housing 4 is sequentially inserted from the opening 4a side from the ferrule 3 side, the opening 4a is closed, and each locking portion 6a of the cap body 6 is locked in each locking hole 4f.

At the time of this insertion, the tip portion 3c and the base portion 3a on the one end side of the ferrule 3 are inserted through the insertion holes 4d, and the flange portion 3b is locked to the overhanging wall portion 4c, where the ferrule 3 is placed in the accommodation hole portion 4b. It is retained by retaining. Further, when the cap body 6 is attached, the bellows portion 5a of the inner boot 5 is inserted into the accommodation hole portion 4b while being compressed. Due to the compressive deformation of the bellows portion 5a, the outer peripheral surface of the bellows portion 5a is pressed so as to be in close contact with the inner peripheral surface side of the accommodation hole portion 4b.
The inner peripheral surface of the bellows portion 5a is pressed against the outer peripheral surface of the optical fiber 2 so as to be in close contact therewith.

When the cap body 6 is attached, the ferrule 3 is always elastically biased in the direction in which the tip 3c of the ferrule 3 is further projected by the elastic force stored in the bellows 5a. At this time, the collar portion 3b is locked to the projecting wall portion 4c, and the ferrule 3 is retained by the connector housing 4 so as not to come off.

The first embodiment of the present invention is configured as described above, and the outer peripheral surface of the bellows portion 5a is accommodated by the inner boot 5 inserted in the accommodation hole portion 4b of the connector housing 4 in a compressed state. Since the inner peripheral surface of the bellows portion 5a is in close contact with the inner peripheral surface of the hole 4b and the inner peripheral surface of the bellows portion 5a is in close contact with the outer peripheral surface of the optical fiber 2, the ferrule from the laid optical fiber 2 side. It is possible to effectively prevent the entry of rain and dew into the 3 side, and a good waterproof effect can be exhibited here.

Further, the receiving hole portion 4 of the connector housing 4
b The inner boot 5 is arranged in the gap between the inner peripheral surface and the outer peripheral surface of the optical fiber 2, which is also advantageous in that it can be made compact.

Furthermore, the elastic force of the inner boots 5 housed in a compressed state always elastically biases the ferrule 3 in the connecting direction, which also has the function of a conventional coil spring. There is also an advantage that a good optical connection state can be secured at the time of connection.

FIG. 7 and FIG. 8 show the second embodiment, in which the housing hole 4b of the connector housing 4 is formed in the shape of a square hole having the same shape as the opening 4a, and the bellows 5a of the inner boot 5 is formed. It may be a structure in which the outer shape is formed in a corresponding square.

The outer shape of the bellows portion 5a of the inner boot 5 may be formed according to the hole shape of the housing hole portion 4b of the connector housing 4, and is not limited to the above-mentioned shapes.

FIG. 9 and FIG. 10 show the third embodiment, and the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, the inner boots 5
The inner diameter of the connecting portion 5b of the ferrule 3 is smaller than the outer diameter of the base portion 3a of the ferrule 3, and the base portion 3a is elastically deformed.
Are connected to each other by press fitting the ends of the.

Further, the ferrule 3 and the optical fiber 2 are caulked at a position where the connecting portion 5b is not provided, as in the first embodiment.

The same effect as described above can be obtained by this embodiment as well.

11 and 12 show the fourth embodiment, and the same components as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the inner boot 5
The inner peripheral surface of the end portion of the connecting portion 5b is provided with a protrusion 5c as a circumferential annular protrusion, and the protrusion 5c is removably fitted into the outer peripheral surface of the base 3a of the corresponding ferrule 3. A circumferential groove 3g is formed in the circumferential direction.

When the end portion of the base portion 3a is press-fitted through the elastic deformation of the connecting portion 5b, the protruding portion 5c is fitted into the circumferential groove 3g and is connected in a state where it is locked and retained. Has been done. Further, the ferrule 3 and the optical fiber 2 are caulked at a position where the connecting portion 5b is not provided, as in the first embodiment.

The same effect as described above can be obtained by this embodiment as well, and the positional deviation between the ferrule 3 and the inner boot 5 can be effectively prevented.

FIGS. 13 to 16 show the fifth embodiment. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, the housing hole 4b of the connector housing 4 is formed in a rectangular shape, and the corresponding crimping cylindrical portion 6c having a rectangular truncated pyramid shape is formed on the end surface of the cap body 6 on the inner boot 5 side. It is formed to project. Then, when the crimping cylinder portion 6c is inserted into the end portion of the inner boot 5 and the cap body 6 is mounted on the connector housing 4, the end portion of the bellows portion 5a of the inner boot 5 is inserted into the accommodation hole portion 4b on the inner peripheral surface side. Is configured to be crimped to.

Therefore, the outer peripheral surface of the bellows portion 5a and the accommodating hole portion 4b.
The close contact with the inner peripheral surface is better obtained, and the airtightness is further improved.

The ferrule 3, the optical fiber 2 and the inner boot 5 are connected to each other by the above-mentioned first to fourth steps.
The structure of any of the above embodiments may be used.

Also, according to this embodiment, not only the same effect as described above can be obtained, but also the waterproof effect is further improved.

When the accommodating hole 4b is circular, the crimping cylinder 6c may be formed in a corresponding truncated cone shape.

17 to 19 show the sixth embodiment, and the same components as those in the fifth embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, the circumferential engaging groove portion 6d is formed on the outer peripheral surface of the crimping cylinder portion 6c in the fifth embodiment.
Is formed, and a circumferential annular protrusion 5d is provided at the end edge of the corresponding bellows 5a of the inner boot 5 so as to be retained in the retaining groove 6d.

Then, the ridge 5d is fitted and locked in the locking groove 6d through the elastic deformation of the bellows 5a, and when the cap body 6 is mounted on the connector housing 4 in this state, The end of the bellows portion 5a of the boot 5 is configured to be pressure-bonded to the inner peripheral surface of the accommodation hole portion 4b.

Therefore, as in the fifth embodiment, the bellows portion 5 is formed.
a The outer peripheral surface and the inner peripheral surface of the housing hole portion 4b are more closely contacted with each other, the airtightness is further improved, and the cap body 6 is provided.
There is also an advantage that when the connector is mounted on the connector housing 4, the positional displacement between the inner boot 5 and the cap body 6 can be effectively prevented.

The ferrule 3 and the optical fiber 2 and the inner boot 5 are connected to each other by the above-mentioned first to fourth connections.
The structure of any of the above embodiments may be used.

The same effect as described above can be obtained by this embodiment as well, and the waterproof effect can be further improved.

20 and 21 show the seventh embodiment. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the optical connector plug 1 is of a multi-pole type for connecting a plurality of optical fibers 2, and the cap body 60 is a plurality (two in this embodiment).
Each of the optical fibers 2 is provided with an insertion hole 6b through which the so-called cap body 6 is connected.

The inner boot 50 has a structure in which a plurality of the inner boots 5 in the above-mentioned embodiment are connected by a substrate portion 5e.

Further, the connector housing 40 has a structure having a plurality of housing holes 4b, and has a structure in which a plurality of so-called connector housings 4 are connected.

The optical connector plug 1 in this case is also assembled in the same manner as described above, and the same effect as described above can be exhibited.

The ferrule 3, the optical fiber 2 and the inner boot 5 may be connected to each other by any of the structures of the above embodiments.

22 and 23 show an eighth embodiment, in which each accommodation hole portion 4 of the connector housing 40 is shown.
b is formed in a rectangular shape, and the bellows portion 5a of the inner boot 50 is also formed in a corresponding rectangular shape. The base portion 5f that connects the two bellows portions 5a is also formed in a bellows shape.

FIGS. 24 and 25 show a ninth embodiment, in which the housing holes 4 of the connector housing 40 are provided.
The opening 4a has a single hole structure in which b is connected.
It is formed in the same rectangular shape as. The corresponding bellows portion 5a of the inner boot 50 is also formed into an integral rectangular shape.

In the seventh to ninth embodiments, the two-pole type optical connector plug 1 is shown, but the same configuration can be made even if the number of poles is three or more.

In each of the above-mentioned embodiments, the structure in which the ferrule 3 is made of metal is disclosed. However, if the ferrule 3 is made of an insulating synthetic resin, the ferrule 3,
Connector housings 4, 40, inner boots 5, 50
If the ferrule 3 and the optical fiber 2 and the inner boots 5 and 50 are connected to each other with an adhesive or the like, and the cap bodies 6 and 60 are all made of an insulating material, all the constituent elements of the optical connector plug 1 are electrically insulating bodies. Therefore, there is an advantage particularly suitable for use in a high voltage environment or an electromagnetic noise environment.

[0069]

As described above, according to the optical connector plug of the present invention, the connector housing having the accommodation hole portion for inserting the ferrule connected to the end portion of the optical fiber from one side and retaining the ferrule on the other side is retained. And an inner boot made of an elastic material having an elastically deformable expandable portion fitted in the optical fiber and a connecting portion connected to the one end of the ferrule, and fitted in the optical fiber. And a cap body that is mounted in a state in which the inner boot is compressed toward the ferrule to close the opening on the one side of the accommodation hole of the connector housing, and the expandable portion of the inner boot is the connector housing. The expansion / contraction portion in a compressed state is formed so as to be in close contact with the outer peripheral surface of the optical fiber and the inner peripheral surface of the accommodation hole portion when the cap body is attached to the There, compact with it exhibited good waterproofing effect by a bullet attack inner boot, which is a compressed state, good optical connection condition can be advantageously ensured.

The inner diameter of the connecting portion of the inner boot is smaller than the outer diameter of the one end of the ferrule, and the end portion of the ferrule is press-fit into the connecting portion. With a structure in which a peripheral groove is formed on the outer periphery of the end portion of the inner boot, and a protrusion is provided on the inner peripheral surface of the connecting portion of the inner boot so as to be retained by the peripheral groove,
There is an advantage that the positional deviation between the ferrule and the inner boot can be effectively prevented.

Furthermore, the inner boot side end surface of the cap body is inserted into the inner boot end portion, and when the inner boot is attached to the connector housing, the inner boot end portion is moved toward the inner peripheral surface of the accommodation hole. The structure in which the crimping cylinder portion for crimping is provided in a protruding manner has the advantages that the airtightness is further improved and the waterproof effect is further improved.

Further, in the case where the outer peripheral surface of the crimping cylinder portion of the cap body is formed with the engaging groove portion for preventing the end edge portion of the inner boot from slipping off, the inner boot and the cap body are separated from each other. There is an advantage that displacement can be effectively prevented.

Further, if the connector housing, the inner boot, the cap body, and the ferrule are each made of an insulating material, all the constituent elements of the optical connector plug serve as an electrical insulator, and a high voltage is applied. It has an advantage that it is particularly suitable for use in an environment or an electromagnetic noise environment.

[Brief description of drawings]

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

FIG. 2 is a perspective view of a connector housing.

FIG. 3 is an explanatory diagram showing the assembly.

FIG. 4 is an explanatory diagram showing the assembly.

FIG. 5 is an explanatory diagram showing the assembly.

FIG. 6 is a sectional view of the same assembled state.

FIG. 7 is a perspective view of a connector housing according to a second embodiment.

FIG. 8 is a perspective view of the inner boot.

FIG. 9 is an explanatory diagram showing assembly in the third embodiment.

FIG. 10 is a sectional view of the same assembled state.

FIG. 11 is an explanatory view showing the assembling in the fourth embodiment.

FIG. 12 is a cross-sectional view of the same assembled state.

FIG. 13 is a sectional view of an assembled state in the fifth embodiment.

FIG. 14 is a perspective view of the cap body.

FIG. 15 is an explanatory diagram showing the assembly.

FIG. 16 is a partially enlarged sectional view of the same assembled state.

FIG. 17 is a sectional view of an assembled state according to the sixth embodiment.

FIG. 18 is an explanatory diagram showing the assembly.

FIG. 19 is a partially enlarged sectional view of the same assembled state.

FIG. 20 is an exploded perspective view showing a seventh embodiment.

FIG. 21 is a perspective view of the connector housing.

FIG. 22 is a perspective view of a connector housing according to an eighth embodiment.

FIG. 23 is a perspective view of the inner boot.

FIG. 24 is a perspective view of a connector housing according to a ninth embodiment.

FIG. 25 is a perspective view of the inner boot.

[Explanation of symbols]

 1 Optical Connector Plug 2 Optical Fiber 2a Core Wire Part 2b Covering Part 3 Ferrule 3a Base Part 3b Collar Part 3c Tip Part 3g Circumferential Groove 4 Connector Housing 4a Opening 4b Accommodating Hole Part 4c Overhanging Wall Part 4f Locking Hole 5 Inner Boot 5a Bellows Part 5b Connecting part 5c Projection part 5d Projection part 6 Cap body 6a Locking part 6b Insertion hole 6c Crimping tube part 6d Locking groove part

Claims (9)

[Claims] 1. An optical connector plug arranged in an optical signal transmission line using an optical fiber, in which a ferrule connected to an end of the optical fiber is inserted from one side and is retained and retained on the other side. An inner boot made of an elastic material having a connector housing having a portion, a stretchable and deformable stretchable portion fitted into the optical fiber, and a connecting portion connected to the one end of the ferrule, and an optical fiber And a cap body that is fitted in a state in which the inner boot is compressed to the ferrule side to close the opening on the one side of the housing hole portion of the connector housing, and the elastic portion of the inner boot. Is a state in which the expandable portion in a compressed state is in close contact with the outer peripheral surface of the optical fiber and the inner peripheral surface of the accommodating hole portion when the cap body is attached to the connector housing. Optical connector plug, characterized in that formed by Uni formed. 2. The optical connector plug according to claim 1, wherein the expandable portion is formed in a bellows shape. 3. The ferrule is made of a metal material, and the connecting portion of the inner boot is inserted into the end portion of the ferrule, and the ferrule, the connecting portion, and the optical fiber are caulked. Optical connector plug. 4. The inner diameter of the connecting portion of the inner boot is formed to be smaller than the outer diameter of the end portion of the ferrule on the one side, and the end portion of the ferrule is press-fit into the connecting portion. The optical connector plug according to claim 2. 5. A peripheral groove is formed on an outer periphery of an end portion of the ferrule on one side, and a projection portion is provided on an inner peripheral surface of a connecting portion of the inner boot so as to be locked by the peripheral groove. The optical connector plug according to claim 4. 6. The inner boot side end surface of the cap body is inserted into an end portion of the inner boot, and
6. A crimping cylinder portion for crimping the end portion of the inner boot to the inner peripheral surface side of the housing hole when mounted on the connector housing is projected.
The optical connector plug described. 7. The optical connector according to claim 6, wherein a locking groove portion is formed on the outer peripheral surface of the crimping cylinder portion of the cap body so as to prevent the end edge portion of the inner boot from being pulled out. plug. 8. The connector housing includes a housing hole portion for inserting ferrules respectively connected to end portions of a plurality of optical fibers from one side and retaining and holding the ferrule to the other side. A plurality of optical fibers are inserted into the cap body, each of which includes a stretchable and deformable stretchable portion that is fitted into the fiber and a connecting portion that is connected to the one end of each ferrule. The optical connector plug according to any one of claims 1 to 7, further comprising: 9. The optical connector plug according to claim 1, wherein the connector housing, the inner boot, the cap body, and the ferrule are each formed of an insulating material.