JP2024024169A - Optical fiber cable with optical connector, method for manufacturing optical fiber cable with optical connector, and optical connector - Google Patents

Abstract

To allow attachment of a standard-size optical connector plug to an optical fiber cable with a relatively small outer diameter by using a crimp ring, and obtain sufficient strength to hold a covering for the optical connector plug without tightening a core wire of an optical fiber.SOLUTION: An aspect of the present invention is an optical fiber cable with an optical connector, and comprises an optical fiber cable and an optical connector. The optical connector includes an optical connector plug having a cylindrical part, a member for crimping for crimping and fixing the optical fiber cable to the optical connector plug, and a flexible tubular member interposed between a covering of the optical fiber cable and the member for crimping. The member for crimping has a cylindrical shape, has, at a first position in an axial direction, at least part of an inner peripheral surface crimped against at least part of an outer peripheral surface of the cylindrical part with a tensile-strength body of the optical fiber cable therebetween, and at a second position in the axial direction, has at least part of the inner peripheral surface crimped against the covering of the optical fiber cable with the tubular member therebetween.SELECTED DRAWING: Figure 4

Description

The present invention relates to an optical fiber cable with an optical connector, a method of manufacturing an optical fiber cable with an optical connector, and an optical connector.

Conventionally, as a method of attaching an optical connector plug to an optical fiber cable having a built-in tensile strength member, an attachment method using a crimp ring is known. In the attachment method using a crimp ring, the outer sheath of the optical fiber cable is generally held by one of the following three methods.

In the first method, a heat shrink tube is attached to the tail of the crimp ring (the end opposite to the optical connector plug to be attached), and the heat shrink tube is heated to shrink. The jacket of the optical fiber cable is held by a heat-shrinkable tube (for example, Non-Patent Document 1). In Non-Patent Document 1, "Metal end of crimp sleeve" corresponds to "crimp ring".
In the second method, a protrusion that protrudes inward is provided on the inner peripheral surface of the rear end of the crimp ring, the crimp ring is crimped to the outer sheath of the optical fiber cable, and the protrusion of the crimp ring is attached to the outer sheath of the optical fiber cable. The outer sheath of the optical fiber cable is held by biting in (for example, Patent Document 1).
In the third method, a tubular elastic member made of an organic material is placed on the inner peripheral surface of the rear end of the crimp ring, and the crimp ring is crimped to the outer sheath of the optical fiber cable. The outer covering is brought into close contact (for example, Patent Document 2). According to Patent Document 2, the elastic member is elastically deformed by crimping, and the elastic member and the outer jacket are brought into close contact with each other, and together with the high coefficient of friction of the elastic member, the optical fiber cable can be sufficiently held.

LC Product Specification 640-252-056 OFS, p32 [searched on July 13, 2020], Internet <URL: https://fiber-optic-catalog.ofsoptics.com/documents/pdf/640-252- 056.pdf＞

Japanese Patent Application Publication No. 3-35207 Patent No. 3340397

Incidentally, in recent years, there has been a demand for optical fiber cables with a diameter smaller than the standard. For example, in indoor data centers, a large amount of optical fiber cables are used for wiring optical transceivers (connections between devices), so there is a desire to reduce the size and weight of each optical fiber cable.
The outer jacket thickness of a standard optical fiber cable with an outer diameter of 2 to 3 mm is about 0.3 to 0.5 mm, but an optical fiber cable with an outer diameter of 1.1 to 1.3 mm is thinner than the standard. The thickness of the outer covering is as thin as 0.15 to 0.2 mm. Further, the amount of tensile strength members built into a small diameter optical fiber cable is smaller than that of a standard outer diameter optical fiber cable.

However, when attaching an optical connector plug to an optical fiber cable with a diameter smaller than the standard, due to the thin outer sheath of the optical fiber cable and the small amount of tensile strength, the conventional configuration is There is a problem with taking it.

In the first method, the heat-shrinkable tube is heated to a high temperature (for example, 90° C. or higher) using a heating means such as a dryer or a heater to shrink the tube. At this time, the outer sheath of the optical fiber cable tends to shrink and deform due to heat, and the internal tensile strength body and the core wire of the optical fiber may be tightly squeezed. In this case, even if the temperature is returned to room temperature, the core of the optical fiber remains tightly constricted, making it impossible for the core of the optical fiber to move (slide) in the axial direction. Therefore, if the ferrules are displaced when the optical connectors are connected and the ferrules come into contact with each other, the core wire of the optical fiber cannot be smoothly displaced in the axial direction in accordance with the displacement of the ferrules and buckles, causing the optical connector to There is a problem in that connection loss worsens.

In the second method, when the outer sheath of the optical fiber cable is thin, it is not possible to obtain enough deformation of the outer sheath to allow the protrusion of the crimp ring to bite into it. Furthermore, if the crimp ring is crimped to increase the amount of contraction, the optical fiber core will be easily constricted, making it impossible for the optical fiber core to move (slide) in the axial direction. Therefore, there is a problem similar to that of the first method (deterioration of connection loss of the optical connector).

In the third method described above, in order to obtain sufficient frictional force by the elastic member, it is necessary to make the outer diameter of the outer sheath of the optical fiber cable and the inner diameter of the tubular elastic member as close as possible. If such dimensions are used, there is a manufacturing problem in that it becomes difficult to insert the elastic member through the outer sheath of the optical fiber cable.

The present invention has been made to solve the above problems, and it is possible to attach a standard-sized optical connector plug to an optical fiber cable with a relatively small outer diameter using a crimp ring, and it also enables the attachment of a standard-sized optical connector plug to an optical fiber cable with a relatively small outer diameter. It is an object of the present invention to provide sufficient attachment strength between an optical connector plug and an outer sheath without tightening the core wire, and to facilitate the insertion of an elastic member into the outer sheath of an optical fiber cable.

A first aspect of the present invention is an optical fiber cable with an optical connector, which includes an optical fiber cable and an optical connector.
The optical fiber cable includes an optical fiber, a sheathing covering the optical fiber, a tensile strength body disposed around the sheath, and an outer shell housing the optical fiber, the sheathing, and the tensile strength body. It has a covering.
The optical connector includes a ferrule that is arranged to protrude from the distal end side and has an insertion hole for the optical fiber formed therein, and a cylindrical part that is provided to protrude from the distal end side opposite to the distal end side. an optical connector plug, a crimping member for crimping and fixing the optical fiber cable to the optical connector plug, and a flexible tubular member interposed between the outer sheath of the optical fiber cable and the crimping member; , is provided.
The crimping member has a cylindrical shape, and at least a portion of the inner circumferential surface is crimped to at least a portion of the outer circumferential surface of the cylindrical portion while sandwiching the tensile strength body of the optical fiber cable at a first position in the axial direction. At least a portion of the inner circumferential surface is crimped to the outer sheath of the optical fiber cable with the tubular member interposed therebetween at a second axial position.

A second aspect of the present invention is a method of manufacturing an optical fiber cable with an optical connector.
This manufacturing method is
removing the outer sheath at the tip of the optical fiber cable to expose a sheath that covers the optical fiber and a tensile strength member disposed around the sheath;
Inserting the optical fiber cable through the notch into a flexible tubular member having a notch formed along the entire area in the axial direction;
passing a cylindrical crimping member through the tubular member;
removing the covering at the tip of the optical fiber cable to expose the optical fiber;
Adhesively fixing the exposed optical fiber to a ferrule provided on the tip side of the optical connector;
The crimp member is slid in the axial direction, and at a first position in the axial direction, at least a part of the inner circumferential surface of the crimp member is placed on the distal end side of the optical connector while sandwiching the tensile strength body of the optical fiber cable. a first crimping step of crimping at least a part of the outer circumferential surface of the cylindrical portion protruding from the end side opposite to the first crimping step;
and a second crimping step of crimping at least a portion of the inner circumferential surface of the crimping member to the outer sheath of the optical fiber cable with the tubular member interposed therebetween at a second axial position.

A third aspect of the present invention is an optical connector attached to an optical fiber cable.
This optical connector is
an optical connector plug having a ferrule arranged to protrude from a distal end side and formed with an insertion hole for an optical fiber; and a cylindrical part protruded from an end side opposite to the distal end side;
a crimping member for crimping and fixing the optical fiber cable to the optical connector plug;
A flexible tubular member is provided between the outer sheath of the optical fiber cable and the crimping member.
The crimping member has a cylindrical shape, and at least a part of the inner peripheral surface of the crimping member has a cylindrical shape while sandwiching the tensile strength member of the optical fiber cable at a first position in the axial direction of the crimping member. and at a second position in the axial direction of the crimping member, at least a part of the inner periphery of the crimping member sandwiching the tubular member. It is arranged at a position where it can be crimped onto the jacket of the optical fiber cable.

According to an aspect of the present invention, it is possible to attach a standard-sized optical connector plug to an optical fiber cable having a relatively small outer diameter using a crimp ring, and the optical Sufficient mounting strength between the connector plug and the outer sheath can be obtained.

FIG. 1 is a perspective view and a side view of an optical fiber cable with an optical connector according to an embodiment. FIG. 1 is an exploded perspective view of an optical fiber cable with an optical connector according to one embodiment. It is a perspective view of the tubular member used for the optical fiber cable with the optical connector of one embodiment. FIG. 1 is a cross-sectional view of an optical fiber cable with an optical connector according to an embodiment. FIG. 3 is a diagram showing components of an optical connector plug according to an embodiment. It is a sectional view of a cylindrical part, a crimp ring, and a tubular member. It is a sectional view of the crimp ring concerning a modification. It is a sectional view of the crimp ring concerning a modification. It is a figure showing the manufacturing method of the optical fiber cable with an optical connector of one embodiment. It is a figure showing the manufacturing method of the optical fiber cable with an optical connector of one embodiment. It is a figure showing the manufacturing method of the optical fiber cable with an optical connector of one embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical connector and an optical fiber cable with an optical connector according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows (a) a perspective view and (b) a side view of an optical fiber cable with an optical connector according to an embodiment. FIG. 2 is an exploded perspective view of an optical fiber cable with an optical connector according to one embodiment. FIGS. 3A and 3B are perspective views of a tubular member used in an optical fiber cable with an optical connector according to one embodiment. FIG. 4 is a sectional view of the optical fiber cable with an optical connector corresponding to the side view of FIG. 1(b).

As shown in FIG. 1, the optical fiber cable with an optical connector includes an optical fiber cable 1 and an optical connector 2.
As shown in FIG. 4, the optical fiber cable 1 includes an optical fiber 11, a core wire 12, a tensile strength member 13, and a jacket 14.
The optical fiber 11 includes a core and a cladding outside the core, and has a structure in which the core has a higher refractive index than the cladding so that light propagates to the central core. Preferably, both the core and the cladding are made of quartz glass or plastic, which has a high transmittance to light.
The core wire 12 is arranged around the optical fiber 11 to protect the optical fiber 11. Although the material of the core wire 12 is not limited, examples thereof include silicone resin, nylon resin, elastomer, and UV-cured resin.
The tensile strength member 13 is provided to relieve the tension generated in the optical fiber 11 covered by the core wire 12 when the optical fiber cable 1 is pulled or bent, and to prevent damage to the optical fiber 11. It will be done. The material of the tensile strength member 13 is not limited, but examples include aramid fibers such as Kevlar (registered trademark), aramid fiber reinforced plastics (KFRP), glass fibers, glass fiber reinforced plastics (KFRP), polyethylene fibers, polyethylene fiber reinforced plastics, etc. Can be mentioned.
The jacket 14 is disposed outside the tensile strength body 13 in order to protect the optical fiber 11 covered by the core wire 12 and the tensile strength body 13 . The material of the outer sheath 14 is not limited, and may be, for example, vinyl chloride resin, elastomer, or the like. The outer diameter of the outer cover 14 is smaller than the inner diameter of the cylindrical portion 31 of the optical connector plug 3, and is, for example, φ1.1 mm to 1.3 mm.

Referring to FIG. 2, the optical connector 2 includes an optical connector plug 3, a tubular member 4, a crimp ring 5, and a boot 6.
Although the optical connector plug 3 is a connector plug compatible with an LC type connector in the example shown in FIG. 2, it is not limited thereto, and may be compatible with other types of connectors such as an SC type connector. A ferrule 33 is disposed on the distal end side of the optical connector plug 3, and a cylindrical portion 31 is provided protruding from the distal end side of the optical connector plug 3. In the case of a standard LC type connector, the outer diameter of the cylindrical portion 31 is φ3.05 mm.
In the present disclosure, as shown in FIG. 2, each component will be described with the side from which the ferrule 33 protrudes defined as the tip side and the opposite side as the distal side, but this is for convenience of explanation. Not too much.

The crimp ring 5 is an example of a crimp member for crimp-fixing (caulking) the optical fiber cable 1 to the optical connector plug 3, and has a cylindrical shape. As shown in FIG. 4, the cylindrical portion 31 of the optical connector plug 3 is housed at the distal end of the crimp ring 5, and the tubular member 4 is housed at the distal end of the crimp ring 5. The length of the crimp ring 5 is preferably in the range of 5 mm or more and 15 mm or less, more preferably 6 mm or more and 12 mm or less.

The tubular member 4 is a member that is interposed between the outer sheath 14 of the optical fiber cable 1 and the crimp ring 5 on the distal side of the cylindrical portion 31 of the optical connector plug 3, and its inner circumferential surface is connected to the optical fiber cable 1. is attached to the outer sheath 14 so as to be in contact with the outer peripheral surface of the outer sheath 14. The outer peripheral surface of the tubular member 4 is set to be slightly smaller than the inner diameter of the crimp ring 5. The inner diameter of the cylindrical member is substantially the same as the outer diameter of the outer sheath 14 of the optical fiber cable 1.
When the crimping jig acts on the crimping ring 5 and the inner diameter of the crimping ring 5 contracts, the tubular member 4 bends inward, so that the outer sheath 14 of the optical fiber cable 1 can be held without being tightened. , the tubular member 4 is flexible. The material of the tubular member 4 is not limited, but may be rubber, soft polyvinyl chloride resin, etc. In this embodiment, silicone rubber is used.

Referring to FIG. 3(a), in one embodiment, a cut 42 is formed along the entire length of the tubular member 4 in the axial direction. When attaching the tubular member 4 around the outer sheath 14 of the optical fiber cable 1, the optical fiber cable 1 only needs to be inserted through the notch 42. The outer peripheral surface of 14 and the inner peripheral surface of tubular member 4 can be brought into close contact.
The tubular member 4A shown in FIG. 3(b) differs from the tubular member 4 shown in FIG. 3(a) in that a partially cut portion 42a is formed at one end of the notch 42. . The cut portion 42a may have any shape as long as it is formed at one end of the notch 42. Forming the cut portion 42a makes it easier to expand the tubular member 4A along the cut 42 when inserting the optical fiber cable 1 into the tubular member 4, which has the advantage of improving insertion workability.
Although the optical fiber cable 1 may be inserted into the tubular member 4 along the axial direction without forming the cut 42 in the tubular member 4, in that case, from the viewpoint of insertion workability, the inner circumferential surface of the tubular member 4 It is necessary to secure a certain amount of clearance between the outer peripheral surface of the outer sheath 14 of the optical fiber cable 1 and the outer peripheral surface of the outer sheath 14 of the optical fiber cable 1. This gap can cause a reduction in the holding force against the outer cover 14 when the inner diameter of the crimp ring 5 is contracted by the crimp jig acting on the crimp ring 5.

The outer diameter of the cylindrical portion 31 has a tensile strength such that the tensile strength body 13 exposed from the optical fiber cable 1 is accommodated between the outer peripheral surface of the cylindrical portion 31 of the optical connector plug 3 and the inner peripheral surface of the crimp ring 5. It is preferable to make the inner diameter of the crimp ring 5 smaller than the tip end side by the thickness of the body 13. The difference between the outer diameter of the cylindrical portion 31 and the inner diameter on the tip side of the crimp ring 5 is preferably 0.1 mm or more and 0.5 mm or less, and more preferably 0.1 mm or more and 0.3 mm or less.

In FIG. 4, in order to fix the optical fiber cable 1 to the optical connector plug 3, at least a part of the inner circumferential surface of the crimp ring 5 is attached to the tensile strength member 13 of the optical fiber cable 1 at the first position P1 on the distal end side in the axial direction. The optical connector plug 3 is crimped onto at least a portion of the outer circumferential surface of the cylindrical portion 31 of the optical connector plug 3 while being pinched, and at least a portion of the inner circumferential surface of the crimp ring 5 is formed into a tubular shape at a second position P2 on the axially distal side of the crimp ring 5. It is crimped to the jacket 14 of the optical fiber cable 1 with the member 4 in between. Note that FIG. 4 does not take into account the deformation of the crimp ring 5, the tubular member 4, and the cylindrical portion 31 of the optical connector plug 3 due to crimp.
In addition to maintaining an appropriate bending diameter of the optical fiber cable 1, the boot 6 covers the crimp ring 5 and a part of the tubular member 4 provided on the outer periphery of the optical fiber cable 1. It is provided to protect the member 4 and the crimped portion of the optical fiber cable 1 from foreign objects, water droplets, and the like.

FIG. 5 shows an exploded view of the optical connector plug 3. As shown in FIG. 5, the optical connector plug 3 includes a ferrule 33, a coil spring 34, and a tube 36.

The optical connector plug 3 has a plug housing 35 made of a first housing part 35A and a second housing part 35B made of resin in order to accommodate the ferrule 33, the coil spring 34, and the tube 36. The first housing part 35A and the second housing part 35B are connected, for example, by a snap fit. The cylindrical portion 31 is fixed to the second housing portion 35B. The second housing portion 35B is manufactured by insert molding using a metal tube corresponding to the cylindrical portion 31 as an insert component.
In the case of an LC type connector, the ferrule body 333 at the tip has an outer diameter of 1.249 mm, and is formed with a through hole for passing the optical fiber 11 of the optical fiber cable 1 therethrough.
The optical fiber 11 is fixed by injecting an adhesive into the through hole, inserting it, and heating it. The adhesive is, for example, a thermosetting adhesive, preferably an epoxy adhesive or an acrylic adhesive.
The coil spring 34 has a distal end supported by the flange portion 332 of the ferrule 33 and a distal end supported by an unillustrated surface of the second housing portion 35B, thereby urging the ferrule 33 toward the distal end side.
The tube 36 is made of a flexible resin such as polytetrafluoroethylene (PTFE), and is attached to the end portion 331 of the ferrule 33. The tube 36 is provided to extend the flange portion 332 of the ferrule 33 toward the cylindrical portion 31.

Next, with reference to FIG. 6, the cross sections and fixing method of the cylindrical portion 31 of the optical connector plug 3, the tubular member 4 to which the optical fiber cable 1 is attached, and the crimp ring 5 will be described.
In FIG. 6, the crimp ring 5 is divided into axial regions A1 to A4 from the distal end side to the distal end side in the axial direction. The inner circumferential surface 52 of the crimp ring 5 includes a first inner circumferential surface 521 (inner diameter D1) of the axial region A1, a second inner circumferential surface 522 (inner diameter D2 (inner diameter D2 < D1)) of the axial region A2, and , including the third inner circumferential surface 523 (inner diameter D3 (D3<D2)) of the axial region A3. The diameter (outer diameter) of the outer peripheral surface 51 of the crimp ring 5 is D4. The axial region A4 is a region where the inner diameter changes linearly from the inner diameter D1 to the inner diameter D2.
Note that it is preferable that D2<D5 so that when the crimp ring 5 is slid with respect to the cylindrical portion 31, the axial region A4 functions as a stopper.

The axial region A1 of the crimp ring 5 is a region that receives a portion of the cylindrical portion 31. The inner diameter D1 of the axial region A1 of the crimp ring 5 is slightly larger than the outer diameter D5 of the cylindrical portion 31 of the optical connector plug 3. The cylindrical portion 31 is attached to the crimping ring 5 such that the tensile strength member 13 of the optical fiber cable 1 is sandwiched between the outer circumferential surface 311 of the cylindrical portion 31 and the first inner circumferential surface 521 of the crimping ring 5. The outer peripheral surface 51 of is crimped. Thereby, the crimp ring 5 is fixed to the cylindrical portion 31.

In FIG. 6, axial regions A2 and A3 of the crimp ring 5 are regions that receive a portion of the distal end side of the tubular member 4. The inner diameter D3 of the axial region A3 of the crimp ring 5 is slightly larger than the outer diameter D6 of the tubular member 4. The tubular member 4 is attached to the crimp ring 5 so that the outer circumferential surface 41 of the tubular member 4 and the third inner circumferential surface 523 of the crimp ring 5 are in contact with each other, and the outer circumferential surface 51 of the crimp ring 5 is crimped. This crimping causes the inner diameter of the third inner peripheral surface 523 of the crimping ring 5 to contract, thereby bending the tubular member 4 and holding the outer sheath 14 of the optical fiber cable 1 attached to the tubular member 4.

The crimping tool for crimping the crimping ring 5 is not limited, but it is a tool that pinches the area to be crimped from both sides. The shape of the crimping hole formed by the crimping tool when sandwiching is not limited, but may be, for example, circular or polygonal such as hexagonal.

In one embodiment, the crimp ring 5 may have a protrusion that protrudes outward from the outer peripheral surface 51. By forming this protrusion, it is possible to increase the force of the crimp ring 5 against the tubular member 4, thereby increasing the holding force of the optical fiber cable 1 against the jacket 14.
FIG. 7 shows crimp rings 5A to 5C as examples of crimp rings having protrusions that protrude outward from the outer circumferential surface 51. As shown in FIG. In FIG. 7, protrusions 513A to 513C are each an example of a first protrusion.

The crimp ring 5A has a protrusion 513A formed in an axial region A3 such that the outer diameter thereof is larger than that of the crimp ring 5 of FIG. 6 . That is, if the outer diameter of the protrusion 513A is DA, then DA>D4. In this example, since the protrusion 513A is formed on the crimp ring 5A, when the protrusion 513A of the crimp ring 5A is crimped, the crimp ring 5A acts firmly on the tubular member 4, making the tubular member 4 larger. Since it is bent, the optical fiber cable 1 attached to the tubular member 4 can be held more strongly.

The crimp ring 5B is formed with a protrusion 513B whose outer diameter increases from the axial region A2 to the axial region A3. The outer diameter DB of the distal end surface of the protrusion 513B is larger than the outer diameter D4 of the axial region A3 of the crimp ring 5 shown in FIG. Note that in the crimp ring 5B, the protrusion is formed so that the outer diameter increases from the distal end to the distal end; Good too.
The crimp ring 5C is an example in which two or more protrusions 513C are formed in the axial region A3. When the outer diameter of the protrusion 513C is DC, DC>D4. In the example of the crimp ring 5C, the number of protrusions 513C is two, but the number of protrusions is not limited.

In one embodiment, the crimp ring 5 may have a protrusion that protrudes inward from the inner peripheral surface 52. By forming this protrusion, it is possible to increase the force of the crimp ring 5 against the tubular member 4, thereby increasing the holding force of the optical fiber cable 1 against the jacket 14.
FIG. 8 shows crimp rings 5D to 5G as examples of crimp rings having protrusions that protrude inward from the inner circumferential surface 52. As shown in FIG. In FIG. 8, each of the third inner circumferential surfaces 523D to 523G is an example of the second protrusion.

The crimp ring 5D has a protruding third inner circumferential surface 523D having a smaller inner diameter than the crimp ring 5 of FIG. 6 over the entire axial region A3. That is, if the inner diameter of the third inner circumferential surface 523D is DD, then DD<D3. In this example, since the third inner circumferential surface 523D having a relatively small diameter is formed on the crimp ring 5D, when the crimp ring 5D is crimped, the crimp ring 5D acts firmly on the tubular member 4. Since it bends more, the optical fiber cable 1 attached to the tubular member 4 can be held more strongly.
The crimp ring 5E has a protruding third inner circumferential surface 523E having a smaller inner diameter than the crimp ring 5 of FIG. 6 in a part of the axial region A3. In other words, the third inner circumferential surface 523E has a portion with an inner diameter D3 (the inner diameter of the third inner circumferential surface 523 of the crimp ring 5 shown in FIG. 6) and a portion with an inner diameter smaller than D3 (a portion with an inner diameter DE smaller than D3). ) and are included. In the example of FIG. 8, the portion having an inner diameter smaller than D3 is formed at the distal end, but the portion is not limited thereto and may be formed at any position in the axial region A3.

In the crimp ring 5F, the third inner circumferential surface 523F of the axial region A3 is a tapered surface that tapers from the distal end side to the distal end side, and the inner diameter of the distal end side of the third inner circumferential surface 523F is D3 (as shown in FIG. The inner diameter of the third inner circumferential surface 523 of the crimp ring 5 shown in FIG. Thereby, the crimp ring 5F has a shape including a protrusion that protrudes inward with respect to the inner circumferential surface 52 of the crimp ring 5 shown in FIG.
The crimp ring 5G has a third inner circumferential surface 523G in an axial region A3 that is tapered from the distal end to the distal end, and the inner diameter of the third inner circumferential surface 523G on the distal end is D3 (Fig. The inner diameter of the third inner circumferential surface 523 of the crimp ring 5 shown in FIG. Thereby, the crimp ring 5G has a shape including a protrusion that protrudes inward with respect to the inner circumferential surface 52 of the crimp ring 5 shown in FIG.

Next, a method for manufacturing an optical fiber cable with an optical connector according to one embodiment will be described with reference to FIGS. 9 to 11. 9 to 11 are diagrams sequentially showing a method of manufacturing an optical fiber cable with an optical connector according to one embodiment.

(1) Process ST1
Referring to FIG. 9, in step ST1, first, the optical fiber cable 1 is passed through the boot 6.
(2) Process ST2
In step ST2, the jacket 14 of the optical fiber cable 1 is removed to expose the core wire 12 covering the optical fiber 11 and the tensile strength body 13 disposed around the core wire 12. At this time, it is exposed in stages so that a portion where only the outer sheath 14 is removed and a portion where the outer sheath 14 and the tensile strength member 13 are removed are formed. Although not limited to, the length from the tip of the jacket 14 to the tip of the core wire 12 (the length of the exposed core wire 12) is in the range of 10 mm or more and 50 mm or less, and the tensile strength member 13 is exposed from the jacket 14. The length ranges from 5 mm to 10 mm.
In step ST2, the optical fiber cable 1 is further inserted into the tubular member 4. Since a notch is formed in the tubular member 4 along the entire area in the axial direction, the optical fiber cable 1 can be easily inserted through the notch.

(3) Process ST3
In step ST3, a cylindrical crimp ring 5 is passed from the distal end side of the tubular member 4 into which the optical fiber cable 1 has been inserted.
(4) Process ST4
Referring to FIG. 10, the core wire 12 is removed at the tip of the optical fiber cable 1 to expose the optical fiber 11. The length of the exposed optical fiber 11 is not limited, but is in the range of 5 mm or more and 15 mm or less.

(5) Process ST5
In step ST5, the exposed optical fiber 11 is adhesively fixed to the ferrule 33 of the optical fiber cable 1. Specifically, a thermosetting adhesive is applied from a dispenser (syringe) containing thermosetting adhesive to the through hole of the ferrule 33 through the end of the cylindrical portion 31 of the optical connector plug 3 and the tube 36 (see FIG. 5). inject. Thereafter, the exposed tip of the optical fiber 11 is inserted into the through hole formed in the ferrule 33. After inserting the tip of the optical fiber 11 into the through hole, the ferrule 33 is heated to harden the thermosetting adhesive.

(6) Process ST6
In step ST6, the crimp ring 5 on the outer periphery of the tubular member 4 is slid in the axial direction toward the distal end, so that the exposed tensile strength body 13 touches the outer peripheral surface of the tubular portion 31 and the inner peripheral surface of the crimp ring 5 (more Specifically, the crimp ring 5 is placed on the outer periphery of the cylindrical portion 31 so as to be sandwiched between the first inner circumferential surfaces 521) shown in FIG. In this case, a portion of the axial region A4 of the crimp ring 5 (see FIG. 6; a portion whose diameter decreases from the inner diameter D1 to the inner diameter D2) serves as a stopper for the crimp ring 5. In this state, at the first position P1 in the axial direction, the crimp ring 5 has at least a portion of the inner circumferential surface of the crimp ring 5 sandwiching the tensile strength member 13 of the optical fiber cable 1 while at least a portion of the outer circumferential surface of the cylindrical portion 31. The crimp ring 5 is disposed at a position where it can be crimped, and at least a part of the inner circumferential surface of the crimp ring 5 can be crimped to the outer sheath 14 of the optical fiber cable 1 with the tubular member 4 in between at the second axial position P2. placed in a suitable position.

(7) Process ST7
In step ST7, at least a part of the inner circumferential surface of the crimp ring 5 is crimped to at least a part of the outer circumferential surface of the cylindrical part 31 while sandwiching the tensile strength body 13 of the optical fiber cable 1 at the first position P1 in the axial direction. (first crimping step). In step ST7, at least a portion of the inner peripheral surface of the crimp ring 5 is further crimp-bonded to the outer sheath 14 of the optical fiber cable 1 with the tubular member 4 in between at the second axial position P2 (second crimp step). In step ST7, the cylindrical portion 31 of the optical connector plug 3 and the crimp ring 5 are firmly fixed, and the outer sheath 14 of the optical fiber cable 1 can be held by bending the tubular member 4 inward.
The crimping at the first position P1 and the second position P2 with respect to the crimping ring 5 is performed when the axial distance between the first position P1 and the second position P2 is less than or equal to the width of the crimping tool (for example, 10 mm or less). may be performed at the same time. This reduces the burden on the process compared to performing the crimping operation twice by sliding the crimping tool.

(8) Process ST8
In step ST8, the boot 6 is slid in the axial direction and engaged with the crimp ring 5.
Through the above steps, the optical fiber cable with optical connector shown in FIG. 1 is completed.

As described above, according to the optical fiber cable with optical connector of one embodiment, at least a portion of the inner circumferential surface 52 of the crimp ring 5 holds the tensile strength body 13 of the optical fiber cable 1 at the first position in the axial direction. It is crimped onto at least a portion of the outer peripheral surface of the cylindrical portion 31 of the optical connector plug 3 while being sandwiched therebetween. Further, at least a portion of the inner circumferential surface 52 of the crimp ring 5 is crimped to the outer sheath 14 of the optical fiber cable 1 with the flexible tubular member 4 interposed therebetween at a second axial position.
As a result, when attaching the optical fiber cable 1 having a relatively small outer diameter to the optical connector plug 3, the flexible tubular member 4 compensates for the difference between the inner diameter of the crimp ring 5 and the outer diameter of the optical fiber cable 1. The outer sheath 14 of the optical fiber cable 1 can be held by absorbing it and bending the tubular member 4 . At this time, the tubular member 4 bends inward due to contraction of the inner circumferential surface of the crimp ring 5 due to the crimp ring 5, but the tubular member 4 does not tighten the core wire 12 of the optical fiber cable 1. Even after crimping, the core wire 12 of the optical fiber cable 1 can move (slide) in the axial direction.

It is preferable that the tubular member 4 has a notch formed along the entire area in the axial direction. The presence of the notch improves workability when inserting the optical fiber cable 1 into the tubular member 4.

In one embodiment, the optical fiber cable 1 is provided with a first protrusion that protrudes outward from the outer circumferential surface of the crimp ring 5 and/or a second protrusion that protrudes inward from the inner circumferential surface of the crimp ring 5. It is also possible to further increase the holding force against the jacket 14.

Although the embodiments of the optical fiber cable with an optical connector, the method for manufacturing the optical fiber cable with an optical connector, and the optical connector of the present invention have been described above, the present invention is not limited to the above embodiments. Moreover, various improvements and changes can be made to the embodiments described above without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case of an LC type connector has been described, but it is also applicable to SC type, MU type, etc. connectors. Further, the present invention is not limited to these, and can also be applied to optical connectors having a similar structure.

DESCRIPTION OF SYMBOLS 1...Optical fiber cable 11...Optical fiber 12...Core 13...Tension body 14...Sheath 2...Optical connector 3...Optical connector plug 31...Cylindrical part 311...Outer peripheral surface 312...Inner peripheral surface 33...Ferrule 331...Terminal Part 332...Flange part 34...Coil spring 35...Plug housing 35A...First housing part 35B...Second housing part 36...Tube 4...Tubular member 41...Outer peripheral surface 5...Crimp ring 51...Outer peripheral surface 511...Engagement groove 513A , 513B, 513C...Protruding portion 52...Inner circumferential surface 521...First inner circumferential surface 522...Second inner circumferential surface 523, 523D, 523E, 523F, 523G...Third inner circumferential surface 6...Boot

Claims (12)

An optical fiber cable with an optical connector,
fiber optic cable and
Equipped with an optical connector,
The optical fiber cable is
optical fiber and
a coating that covers the optical fiber;
a tensile strength member disposed around the covering;
comprising the optical fiber, the covering body, and a jacket housing the tensile strength body,
The optical connector is
an optical connector plug having a ferrule arranged to protrude from a distal end side and in which an insertion hole for the optical fiber is formed; and a cylindrical part provided to protrude from an end side opposite to the distal end side;
a crimping member for crimping and fixing the optical fiber cable to the optical connector plug;
a flexible tubular member interposed between the outer sheath of the optical fiber cable and the crimping member;
The crimping member has a cylindrical shape, and at least a portion of the inner circumferential surface is crimped to at least a portion of the outer circumferential surface of the cylindrical portion while sandwiching the tensile strength body of the optical fiber cable at a first position in the axial direction. and at least a portion of the inner circumferential surface is crimped to the outer sheath of the optical fiber cable with the tubular member interposed therebetween at a second axial position;
Fiber optic cable with optical connector. The tubular member has a notch formed along the entire area in the axial direction.
An optical fiber cable with an optical connector according to claim 1. The crimping member has a first protrusion that protrudes outward from the outer peripheral surface.
An optical fiber cable with an optical connector according to claim 1 or 2. The crimping member has a second protrusion that protrudes inward from the inner circumferential surface.
An optical fiber cable with an optical connector according to claim 1 or 2. The crimping member has a second protrusion that protrudes inward from the inner circumferential surface.
An optical fiber cable with an optical connector according to claim 3. A method for manufacturing an optical fiber cable with an optical connector, the method comprising:
removing the outer sheath at the tip of the optical fiber cable to expose a sheath that covers the optical fiber and a tensile strength member disposed around the sheath;
Inserting the optical fiber cable through the notch into a flexible tubular member having a notch formed along the entire area in the axial direction;
passing a cylindrical crimping member through the tubular member;
removing the covering at the tip of the optical fiber cable to expose the optical fiber;
Adhesively fixing the exposed optical fiber to a ferrule provided on the tip side of the optical connector;
The crimp member is slid in the axial direction, and at a first position in the axial direction, at least a part of the inner circumferential surface of the crimp member is placed on the distal end side of the optical connector while sandwiching the tensile strength body of the optical fiber cable. a first crimping step of crimping at least a part of the outer circumferential surface of the cylindrical portion protruding from the end side opposite to the first crimping step;
a second crimping step of crimping at least a part of the inner circumferential surface of the crimping member to the outer sheath of the optical fiber cable with the tubular member sandwiched therebetween at a second axial position;
A method of manufacturing an optical fiber cable with an optical connector, including: performing the first crimping step and the second crimping step simultaneously;
A method of manufacturing an optical fiber cable with an optical connector according to claim 6. An optical connector attached to an optical fiber cable,
an optical connector plug having a ferrule arranged to protrude from a distal end side and formed with an insertion hole for an optical fiber; and a cylindrical part protruded from an end side opposite to the distal end side;
a crimping member for crimping and fixing the optical fiber cable to the optical connector plug;
a flexible tubular member interposed between the outer sheath of the optical fiber cable and the crimping member;
Equipped with
The crimping member has a cylindrical shape, and at least a part of the inner peripheral surface of the crimping member has a cylindrical shape while sandwiching the tensile strength member of the optical fiber cable at a first position in the axial direction of the crimping member. and at a second position in the axial direction of the crimping member, at least a part of the inner periphery of the crimping member sandwiching the tubular member. disposed at a position where it can be crimped onto the outer sheath of the optical fiber cable;
optical connector. The tubular member has a notch formed along the entire area in the axial direction.
The optical connector according to claim 8. The crimping member has a first protrusion that protrudes outward from the outer peripheral surface.
The optical connector according to claim 8 or 9. The crimping member has a second protrusion that protrudes inward from the inner circumferential surface.
The optical connector according to claim 8 or 9. The crimping member has a second protrusion that protrudes inward from the inner circumferential surface.
The optical connector according to claim 10.

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