JPH0440175Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of an optical fiber connector.

[Conventional technology]

There are various structures of optical fiber connectors (hereinafter referred to as connectors) for connecting optical fiber cables, and Figure 4 shows an example of this type of connector attached to an optical fiber cable (hereinafter referred to as cable). A part of something is shown in cross section.

When attaching the connector to the cable 1, the outer sheath 2 is removed to expose the fibrous reinforcing member 3 and the inner cable 4. Inner cable 4
is composed of a fiber core wire 4a and an internal insulator 4b covering its outer periphery, and a predetermined amount of the inner insulator 4b is peeled off to expose the fiber core wire 4a. On the other hand, the connector 5 includes a tightening nut 6 and a clamp ring 7 for fixing the reinforcing member 3 of the cable 1 to the connector body, a bushing 8 that covers the rear part of the connector 5 including the cable 1, and a front outer part that forms the connector body. It consists of a tube 9, a rear outer tube 10, a ferrule 11 that is fixed over the tip of the cable 1, and a coupling nut 13 containing a spring 12 for coupling to a mating connector (not shown).

The tightening nut 6 has a hole 6a penetrated through the center.
It is a metal member with a female thread 6b carved into the inner circumferential surface of one end of a. The clamp ring 7 is a cylindrical body made of resin, and has a hole 7a in the center through which the reinforcing member 3 portion of the cable 1 with the jacket 2 removed is inserted.
Further, a tapered surface 7b is formed on the outer circumferential surface, the diameter of which decreases from approximately the middle portion toward the end surface. The bushing 8 is an elastic member in which a hole 8a is formed in the center to cover the jacket 2 of the cable 1 and the rear part of the connector 5. The rear outer cylinder 10 has a metal cylindrical body, has a hole 10a in the center, and has an outwardly opening tapered part 10b corresponding to the tapered surface 7b of the clamp ring 7 at one end of the hole 10a. has been done. Also, one end of the outer peripheral surface on the tapered portion 10b side is provided with a male thread 10c that engages with the female thread 6b of the tightening nut portion 6, and near the other end is provided with a male thread 10c that engages with the female thread of the front outer cylinder 9, which will be described later. A matching male thread 10d is provided. The front outer cylinder 9 is made of metal and has a hole 9 in its center.
a is bored, and a female thread 9 is provided on the inner peripheral surface of one end side of the hole 9a to be screwed into the male thread 10d of the rear outer cylinder 10.
b is engraved. The other end of the hole 9a is continuous with a hole 9c through which a ferrule 11, which will be described later, is inserted.

The ferrule 11 is a metal member formed into a substantially cylindrical shape, and has a hole 11a opened at one end in the center, and a small hole 11b continuous to the hole 11a through which the fiber core wire 4a can be inserted at the other end. It is installed through. Further, a collar 11c is formed approximately at the center of the outer peripheral surface. The coupling nut 13 is a metal member having a hole 13a in the center and an engagement groove 13b on the outer periphery.

Next, as a procedure for attaching the connector 5 to the cable 1, the bushing 8 is first passed through the cable 1, and then the tightening nut 6 is passed through the cable 1. As a terminal treatment for the cable 1, a reinforcing member 3 and an internal insulator 4b are used.
After exposing the required lengths of the fiber core wires 4a and 4a, the clamp ring 7 is passed through the cable 1 and placed on the reinforcing member 3, leaving the end face on the tapered surface 7b side behind. Then, the reinforcing member 3 led out from the end face on the tapered surface 7b side is folded back to cover the tapered surface 7b almost uniformly. Next, the rear outer cylinder 10
is passed through the cable 1 with the opening side having the tapered part 10b first, and by fitting the tapered part 10b onto the tapered surface 7b of the clamp ring 7, the reinforcing member 3 is connected to the tapered part 10b of the rear outer cylinder 10 and clamped. It is inserted between the tapered surfaces 7b of the ring 7. While maintaining this state, the male thread 10c of the rear outer cylinder 10
The female thread 6c of the tightening nut 6 is screwed together, and the tightening nut 6 is screwed forward. Therefore, the clamp ring 7 is pressed by the tightening nut 6, and the reinforcing member 3 is clamped and fixed between the tapered portion 10b and the tapered surface 7b.

Next, the ferrule 1 is inserted into the fiber core 4a of the inner cable 4 protruding from the rear outer tube 10.
Cover with 1.

Then, the fiber core wire 4a is inserted into the pore 11c of the ferrule 11, and the adhesive 14 is injected into the cavity of the ferrule 11 with the tip surface of the fiber core wire 4a protruding slightly outward from the tip surface of the ferrule 11. Fix the inner cable 4 and ferrule 11.

FIG. 5 shows an enlarged sectional view of the main part of the ferrule, and FIG. 5a shows the ferrule 11 used in the connector 5 of FIG. 4. The ferrule 11' in FIG. 1B is not integrally processed, but a bushing 15 made of hard stone such as ceramic is fitted and fixed to the tip of the ferrule 11'. The pores 15a drilled in the separately processed bush 15 in this way
is the pore 1 drilled in the integrally processed ferrule 11.
The inner diameter can be made smaller and more accurate than 1c.

After fixing the ferrule 11 and the inner cable 4 with the adhesive 14 as described above, the fiber core wire 4
Polishing is performed so that the tip end surface of a and the tip end surface of the ferrule 11 are on the same plane. Next, attach the front outer cylinder 9 to which the spring 12 has been fitted in advance and tighten the coupling nut 13.
into the hole 13a.

Next, insert the front outer cylinder 9 into the ferrule 11 through the hole 9a.
At the same time, it is fitted onto the rear outer cylinder 10 and the female thread 9 is inserted.
b is screwed onto the male thread 10d of the rear outer cylinder 10.
Then, as the front outer cylinder 9 spirals over the rear outer cylinder 10, the ferrule 11 is moved by the front outer cylinder 9 to the collar 11.
c is pressed against the peripheral edge of the hole 10a of the rear outer cylinder 10 and fixed. Finally, the bushing 8 is placed over the tightening nut 6 as shown to complete the harness.

When connecting with a mating connector, the engagement groove 13b of the coupling nut 13 is engaged with a protrusion (not shown) of the mating connector.

[Problem that the invention attempts to solve]

The conventional connector 5 constructed as described above has a large number of parts, and some parts are threaded or tapered, making it expensive. Furthermore, since an adhesion process is required, assembly time including drying time is required, and workability is not good.

Therefore, the purpose of this invention is to solve the above-mentioned problems, and to create an inexpensive and easy-to-assemble product that does not require threaded or tapered parts, and also eliminates the need for gluing. An object of the present invention is to provide an optical fiber connector.

[Means for solving problems]

The present invention provides an optical fiber connector to be connected to an optical fiber cable in which the fiber core wire is sequentially covered with an internal insulator, a reinforcing member, and an outer sheath. a metal inner cylinder having a hole into which the sleeve is tightly fitted and into which the internal insulator is inserted at the other end; a hole into which one end of the inner cylinder is press-fitted; and a tip of the sleeve inside the inner cylinder. and a ferrule having a thin hole into which the fiber core wire protruding from the inner tube is inserted, and the ferrule protrudes from the other end of the inner cylinder and is inserted into the sleeve by caulking the outer peripheral portion where the sleeve is located. At the same time, the inner insulator inserted into the inner cylinder is crimped and fixed by crimping the outer periphery of the other end of the inner cylinder, and the inner insulator is further placed over the outer periphery of the inner cylinder. The reinforcing member is crimped and fixed to the inner outer peripheral portion using a crimping ring.

With the structure described above, the inner cylinder holding the sleeve inside is press-fitted and fixed at the distal end to the ferrule, and by pressing the outer periphery, the inner cylinder is attached to the core wire of the inner cable inserted from the rear end. It is crimped and fixed via a sleeve. The rear end portion of the inner cylinder inserted into the outer sheath of the cable is crimped and fixed to the inner cable by being pressed from above the outer sheath. In addition, the reinforcing member exposed from the outer jacket is placed on the outer circumferential surface of the inner cylinder, and a crimp ring is fitted over the reinforcing member and the outer sheath, and then the reinforcing member and the outer sheath are removed by pressing the crimp ring. Crimp and fix on the inner cylinder.

Therefore, it has become possible to fix the fiber core wire and the inner insulator portion covering the fiber core wire to the ferrule via the sleeve and the inner tube without using an adhesive. Further, the reinforcing member and the outer cover can be crimped and fixed between the crimping ring and the inner cylinder by simply pressing the crimping ring fitted onto the inner cylinder. Therefore, it is possible to improve the connection work with the cable, and to obtain an inexpensive optical fiber connector with a small number of parts that does not require thread processing or taper processing.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows a partially sectional view of the connector. That is, the connector 20 includes an inner cylinder 22 that holds the sleeve 21 therein, and an inner cylinder 22 that holds the sleeve 21 therein.
2, a crimping ring 23 that is placed over the rear end of the inner tube 22 to crimp and fix the cable 1, a ferrule 24 that is press-fitted into the tip of the inner cylinder 22, and a coupling nut 26 containing a spring 25 for coupling with the mating connector. and a bushing 2 that covers the rear of the connector containing cable 1.
It is composed of 7.

The inner cylinder 22 is a metal cylinder having a hole 22a slightly larger than the outer diameter of the inner cable 4 formed through the shaft center. A reinforcing member 3 and an inner cable 4 are attached to one end of the inner tube 22 within the outer sheath 2 of the cable 1.
A first cylindrical body 22b is formed to be inserted between the two. A thick-walled second cylindrical body 22c is provided continuously from the first cylindrical body 22b. The dimensions are set such that one reinforcing member 3 can be crimped and fixed. A third cylindrical body 22d elongated in the axial direction is integrally formed from the second cylindrical body 22c, and the tip portion of the third cylindrical body 22d is press-fitted into a ferrule 24, which will be described later. The sleeve 21 is made of a metal pipe material, for example, and its outer diameter is the same as the hole 22 of the inner cylinder 22.
The inner diameter of the inner hole 21a formed at the center of the shaft is such that the fiber core wire 4a can be inserted therethrough.

The crimp ring 23 is a metal cylinder, and the inner diameter of the hole 23a formed at one end is equal to that of the inner cylinder 22.
The first cylindrical body 22b is dimensioned to allow insertion of the outer sheath 2 portion into the cable 1 as described above. Further, the inner diameter of the hole 23b following the hole 23a is slightly larger than that of the hole 23a.
The dimensions are set such that the reinforcing member 3 of the cable 1 can be crimped and fixed in cooperation with the second cylindrical body 22c of the inner cylinder 22. The ferrule 24 is made of a synthetic resin material and has a cylindrical shape, and has a cylindrical part 24a on one end into which a coupling nut 26, which will be described later, is fitted. Protruding tsuba 2
4b is formed.

Furthermore, a cylindrical portion 24c that fits into a mating connector is provided from the collar 24b. Mata ferrule 24
Holes 24d, 24e, and 24f having different inner diameters are sequentially formed at the axial center from the end surface side of the cylindrical portion 24a. That is, the third cylindrical body 22d of the inner cylinder 22 is press-fitted into the hole 24d, the sleeve 21 protruding from the tip of the inner cylinder 22 is fitted into the hole 24e, and the fiber core wire 4a is inserted into the hole 24f. Ru. The continuous portion of the holes 24e and 24f has a taper 2.
4g, and the tip of the fiber core wire 4a is guided by the taper 24g and inserted into the hole 24f.

The coupling nut 26 is a cylindrical body made of synthetic resin or zinc die-casting, and has a hole 26a into which the cylindrical portion 24a of the ferrule 24 is inserted from one end, and a hole that is continuous with the hole 26a and opens at the other end. 26b
is formed. The collar 24b of the ferrule 24 is inserted into the hole 26b, and the spring 25 is accommodated therein. Further, the peripheral wall of the hole 26b is provided with an engaging groove 26e that engages with a protrusion provided on the mating connector when the mating connector is coupled.

The bushing 27 is a molded part made of an elastic material, and has a hole 27a in the center through which the cable 1 can be inserted closely, and a connector 20 connected to the hole 27a.
An opening 27b surrounding the rear part of the inner cylinder 22 is formed on the inner wall of the opening 27b.
An engaging protrusion 27c that engages with is provided.

The following procedure is used to attach the cable 1 to the connector 20 of the present invention, which is constructed of the various parts as described above. First, hole 2 of inner cylinder 22
The sleeve 21 is fitted into the sleeve 2a, and their relative positions are determined using a positioning jig (not shown).

Next, while maintaining this state, the outer peripheral surface of the inner cylinder 22, that is, the second cylindrical body 22 of the third cylindrical body 22d.
The outer peripheral surface near side c is crimped in the direction of the arrow (see FIG. 1b) using a crimping jig (not shown). For this reason, the sleeve 21 is temporarily fixed to the inner tube 22 with its tip exposed from the third cylindrical body 22d of the inner tube 22. The sleeve 21 like this was manufactured separately for the inner cylinder 22.
This is because it is difficult to provide a long and narrow inner hole 21a through which the fiber core wire 4a is inserted. Next, after the spring 25 is fitted onto the cylindrical portion 24a of the ferrule 24, the coupling nut 26 is placed over the cylindrical portion 24a with the hole 26 side first. Therefore, the spring 25 is connected to the collar 24b of the ferrule 24 and the step 26 of the coupling nut 26.
d. While maintaining this state, insert the third inner cylinder 22 into the hole 24d of the ferrule 24.
Press fit from the cylindrical body 22d side. Therefore, the inner cylinder 22
is the sleeve 21 protruding from the third cylindrical body 22d.
is inserted into the hole 24e of the ferrule 24, and the third cylindrical body 22d is inserted into the hole 24e of the ferrule 24.
4d, and its tip surface is connected to hole 24d and hole 24.
It is fixed by being brought into contact with the stepped portion 24h formed by e. Note that even if the coupling nut 26 is subsequently moved in the direction of being removed from the ferrule 24, the rear end surface 26e of the coupling nut 26 remains in contact with the flange 22c-1 of the inner cylinder 22.
There is no risk of it coming off the ferrule 24 as it comes into contact with the ferrule 24.

Thus, as shown in Figure 1b, the sleeve 2
1. The inner cylinder 22, ferrule 24, spring 25 and coupling nut 26 are assembled with each other to assemble the connector assembly 30.

On the other hand, as shown in FIG.
, and then insert the crimp ring 23 with the hole 23a side first. Then, as shown in FIG. 1B, the outer sheath 2 of the cable 1 is removed to expose only the required length of the reinforcing member 3 and the inner cable 4. Furthermore, as shown in FIG. Cut into. For this reason, the end surface of the fiber core wire 4a obtained by cutting has a finished surface equivalent to a polished surface. The cable 1 which has undergone the terminal treatment as described above is inserted from the inner tube 22 side of the connector assembly 30 as shown in FIG. 3a. Then, the inner cable 4 inserted into the hole 22a of the inner tube 22 passes the fiber core wire 4a through the inner hole 21a of the sleeve 21, the holes 24e and 24f of the ferrule 24, and the tip end surface of the fiber core wire 4a is inserted into the inner hole 21a of the sleeve 21, and the holes 24e and 24f of the ferrule 24. It is made to protrude slightly outward from the tip end surface of the cylindrical portion 24c. (Not shown) Also, the first cylindrical body 22b of the inner tube 22 is inserted between the reinforcing member 3 covered with the outer sheath 2 and the outer peripheral surface of the inner cable 4. The reinforcing member 3 exposed from the end surface of the outer cover 2 is cut into a predetermined length and pulled out to cover the second cylindrical body 22c of the inner cylinder 22. Next, the cylindrical part 2 of the ferrule 24
4c is covered with a pressing jig 40, and the end surface of the fiber core wire 4a protruding from the end surface of the ferrule 24 is pressed by the bottom surface of the recess 40a of the pressing jig 40, so that the end surface of the fiber core wire 4a and the cylindrical portion are pressed. The tip surfaces of 24c are made on the same plane.

While maintaining this state, a suitable coating is applied to the outer jacket 2 portion of the cable 1 that covers the first cylindrical body 22b of the inner tube 22 and the outer peripheral portion of the third cylindrical body 22d of the inner tube 22 exposed from the ferrule 24. A pressing force is applied in the direction of the arrow in the figure by the pressing means. Therefore, the first cylindrical body 22b of the inner tube 22 is crimped and fixed onto the internal insulator 4b of the inner cable 4, and the third cylindrical body 22d of the inner tube 22 is crimped to the fiber core wire 4a via the sleeve 21. Fixed.

Next, the reinforcing member 3 exposed from the end surface of the jacket is covered with a substantially uniform thickness on the outer peripheral surface of the second cylindrical body 22c of the inner cylinder 22, and then the crimp ring 23, which has been passed through the cable 1 in advance, is is placed over the reinforcing member 3 and the outer sheath 2 as shown in FIG. 3b. Then, applying a pressing force in the direction of the arrow to the outer peripheral surface of the crimp ring 23 using an appropriate pressing means, the reinforcing member 3 is inserted between the inner peripheral surface of the hole 23b of the crimp ring 23 and the outer peripheral surface of the second cylindrical body 22c. Crimp and fix. At the same time, the jacket 2 and the reinforcing member 3 are crimped between the hole 23a of the crimping ring 23 and the first cylindrical body 22b, and the connector assembly 30 is connected to the cable 1. Finally, the bushing 27 that has been passed through the cable 1 in advance is moved and placed over the connecting portion between the connector assembly 30 and the cable 1, thereby completing the assembly of the connector 20. The bushing 27 has an engaging protrusion 27c provided on the inner peripheral surface that engages with the flange 22c-1 of the inner cylinder 22, and also engages the rear end surface 26e of the coupling nut 26.
The bushing 27 is assembled with the front end surface thereof in contact with the bushing 27.

[Effect of idea]

As is clear from the above explanation, this idea involves press-fitting a metal inner cylinder with a built-in sleeve into a synthetic resin ferrule in advance, and crimping the inner cylinder onto the fiber core of the inner cable via the sleeve. At the same time, it is also crimped and fixed to the internal insulator portion that covers the fiber core wire. Further, the reinforcing member and the outer sheath are interposed between the inner cylinder and the crimp ring fitted onto the inner cylinder, and the structure is such that the reinforcing member and the outer sheath can be reliably crimped and fixed to the inner cylinder by pressing the crimp ring. As a result, the number of parts can be reduced without using expensive parts with screws or tapered parts, and workability can also be improved since there is no need for gluing.
An inexpensive and miniaturized optical fiber connector can be obtained. In addition, since the fiber core wire is fixed to the sleeve and inserted deep into the ferrule hole,
The fiber core wire can be reliably positioned and fixed to the ferrule, and an optical fiber connector with high connection reliability with a mating connector can be obtained.

[Brief explanation of the drawing]

Fig. 1a is a partially sectional side view showing the connector according to the present invention attached to a cable, Fig. 1b is a partially sectional side view of the connector before being attached to the cable, and Figs. 2a, b, and c are Figures 3a and 3b are perspective views illustrating the cable terminal processing process; Figures 3a and 3b are partially sectional side views illustrating the process of attaching the connector to the cable; and Figure 4 is a diagram showing a conventional connector attached to the cable. FIGS. 5a and 5b are partially sectional side views and enlarged sectional views of essential parts of the ferrule. 1... Optical fiber cable, 2... Jacket, 3...
...Reinforcement member, 4...Inner cable, 4a...
Fiber core wire, 5, 20... Optical fiber connector, 11, 24... Ferrule, 21... Sleeve, 21a... Hole, 22... Inner cylinder, 23... Crimp ring, 24... Ferrule, 24d, 24e ，
24f... hole.

Claims (1)

[Scope of utility model registration request] In an optical fiber connector connected to an optical fiber cable whose periphery is sequentially covered with an internal insulator, a reinforcing member, and an outer sheath, and whose terminals are treated so that each of them is sequentially exposed, a thin hole through which the fiber core is inserted. a metal inner cylinder having a hole at one end into which the sleeve is tightly fitted and into which the internal insulator is inserted at the other end; and a hole into which one end of the inner cylinder is press-fitted. and a ferrule having a thin hole through which the fiber core wire protruding from the tip of the sleeve in the inner cylinder is inserted, and a crimp ring, the outer periphery protruding from the other end of the ferrule of the inner cylinder and on which the sleeve is located. crimping and fixing the sleeve and the fiber core wire inserted into the sleeve, and crimping and fixing the inner insulator inserted into the inner cylinder by crimping the outer periphery of the other end of the inner cylinder. The optical fiber connector is further characterized in that the reinforcing member placed over the outer periphery of the inner cylinder is crimped and fixed to the outer periphery of the inner cylinder by the crimping ring.