JP2580643Y2 - Connection structure of optical cable in optical connector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector used for connection of an optical fiber line, and relates to a structure of a connecting portion between the optical connector housing and an optical cable containing the optical fiber line.

[0002]

2. Description of the Related Art Generally, an optical fiber line is connected via a ferrule attached to the end of the optical fiber line, and an optical connector is constructed by holding the ferrule. As such an optical connector, for example,
There is one disclosed in JP-A-3-167506. This optical connector has upper and lower housings for holding a plurality of ferrules, and each ferrule is connected to an optical fiber line held in an optical cable.

[0003] For this reason, the front end of the optical cable is attached to the rear end of the connector housing, and a plurality of optical fiber wires extending in the optical cable are connected to ferrules provided in the connector housing. I have. Here, since the optical cable is easily subjected to an external force, for example, when the optical cable is pulled by the external force, if the pulling force reaches an internal optical fiber line, an optical signal through the optical fiber line is transmitted. There is a problem that transmission efficiency is reduced.

For this reason, in the optical connector disclosed in the above-mentioned publication, a first reinforcing fiber fixing pipe is inserted through the jacket of the optical cable, and the reinforcing fiber exposed from the end of the cable is folded over the first fixing fiber fixing pipe. A second reinforcing fiber fixing pipe made of a material softer than the first fixing pipe is inserted through the folded reinforcing fiber, and the second fixing pipe is sandwiched between upper and lower housings of the connector, and the second fixing pipe is fixed. The reinforcement pipe is deformed so that the reinforcing fibers are fixed and held between the fixing pipes.

[0005]

In this case, the reinforcing fiber is sandwiched between the two pipes and fixedly held, and the two pipes are sandwiched and fixedly held by the upper and lower housings. The part is fixedly held in the optical connector housing. Therefore, even when the optical cable is pulled by an external force, the optical fiber line rarely receives the pulling force. However, in this connection structure, only the reinforcing fibers are fixed and held, and the jacket located on the inner diameter side of the first reinforcing fiber fixing pipe is not particularly fixed. For this reason, when the optical cable is twisted by an external force, the jacket is rotated, the internal optical fiber wire is twisted, which causes a problem that the optical fiber wire is damaged or the transmission efficiency of the optical signal is reduced. is there.

The present invention has been made in view of such a problem.
The end of the optical cable can be firmly connected to the optical connector housing, so that even if the optical cable is pulled or twisted, this pulling or twisting force does not reach the internal optical fiber line. An object of the present invention is to provide an optical cable coupling structure.

[0007]

In order to achieve the above object, in the present invention, a first pipe member is inserted from the end of the optical cable to the inner peripheral side of the reinforcing fiber so as to surround the optical fiber line, and the end of the optical cable is inserted. The reinforcing fiber exposed from the wrapping is folded back on the jacket member and is divided into a plurality of bundles, and the second pipe member having a plurality of projections forming a groove-like projection space to the outer peripheral side is folded back and bundled. The reinforcing fiber thus obtained is fitted over the jacket member so as to enter the groove-shaped projecting space, and the second pipe member is press-deformed while caulking the protruding portion, and the press-deformed second member is pressed. The two-pipe member is held by the housing of the optical connector, and the distal end of the optical cable is connected to the optical connector.

[0008]

In the case of the above coupling structure, each reinforcing fiber folded and bundled by the crimped projection is clamped, and the jacket member is clamped between the first and second pipe members. . Therefore, when the second pipe member is fixedly held by the connector housing, not only the reinforcing member but also the jacket member can be held by the connector housing, and even when the optical cable is pulled or twisted, these pulling forces are exerted. The torsional force is received at the fixing portion, and the force is not applied to the internal optical fiber line.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an example in which a two-core optical connector is connected to the end of the optical cable 5 having the coupling structure according to the present invention. This two-core optical connector has upper and lower connector housings 10 and 20 which are assembled integrally by bolting, and two ferrules 1 are provided therein.
Is attached. The optical cable 5 is constituted by covering two optical fiber lines 6 with a cylindrical jacket 7 having a reinforcing fiber (Kevlar fiber) 8 on the inner peripheral side. The end of the optical cable 5 is connected to the upper and lower connector housings 10 and 20 via the cable hood 30, and in this state, the optical fiber line 6 protruding into the housings 10 and 20 from the end of the optical cable 5 through the cable hood 30. Ferrule 1 is connected to the tip of. At this time, the optical fiber line 6
Is exposed on the tip side of the ferrule 1.

The lower connector housing 10 has a ferrule holding portion 11 having two front and rear ferrule receiving holes 11a at a front end thereof, and a housing portion 13 extending integrally and connected to the rear side of the ferrule holding portion 11.
And a hood receiving portion 18 formed on the rear side of the housing portion 13. The hood receiving portion 18 is integrally formed using a resin material. Ferrule holding hole 1 of ferrule holding section 11
1a are formed side by side on the left and right.
As shown in the figure, a guide hole 11 into which the ferrule 1 is fitted.
b. A lock lever receiving groove 11c extending forward and backward is formed between the portions forming both ferrule holding holes 11a.

The housing portion 13 is formed in a container shape opened upward. A pair of partition walls 14 extending forward and backward and a boss 16 having a bolt hole 16a penetrating vertically are provided inside the housing portion 13. ing. Further, a portion of the peripheral wall facing the partition wall 14 is thickened to form a pair of positioning walls 15, and a positioning hole 15a is formed in the positioning wall 15. The hood receiving portion 18 is formed with a pair of guide pins 19 projecting upward. A semicircular opening 18a is formed in the rear wall, and a guide groove 18b is formed between the rear wall and the guide pin 19. Further, a receiving groove 18c extending forward and backward is formed on the bottom surface.

The upper connector housing 20 is also integrally molded with resin, and is formed so as to cover and attach to the housing portion 13 and the hood receiving portion 18 of the lower connector housing 10. Therefore, the upper connector housing 20 includes a cover body 21 and a hood cover 28 corresponding to the housing 13 and the hood receiving portion 18 of the lower connector housing 10. At the center of the cover main body 21, a bolt hole 21a facing the bolt hole 16a of the housing portion 13 is formed. Further, a semicircular opening (not shown) facing the opening 18a of the hood receiving portion 18 is formed in a rear wall of the hood cover portion 28, and an upper inner surface thereof faces the receiving groove 18c of the hood portion 18. The receiving groove 28c (see FIG. 4) is formed.

At the center of the front of the cover body 21,
A lock lever 23 that is partitioned by a pair of slits 23a and protrudes forward is formed. Due to the slit 23a, the lock lever 23 can be elastically deformed up and down around the base connecting portion, and the elastic deformation allows the tip lock projection 24 to be locked to the lock portion of the mating member or to release this lock. And so on.

Further, as shown in FIG.
A press plate 25 protruding downward is formed on the lower side (inner side) of 1. When the upper connector housing 20 is attached to the lower connector housing 10, the presser plate 25 covers the space between the partition wall 14 and the positioning wall 15 from the rear side as shown by a two-dot chain line in FIG. 2. Position. Further, positioning projections 26 projecting downward are provided on the lower surfaces of the left and right walls of the cover body 21. The positioning projection 26 enters the positioning hole 15a when the upper connector housing 20 is attached to the lower connector housing 10.

The cable hood 30 has a cylindrical hood portion 31 having a through-hole for receiving the optical cable 5 and a lateral wall 3.
2 and a vertical wall 33. Food part 3
A pair of upper and lower slots 31a are formed on the front side of the vertical wall 33 in FIG. 1, and a pin guide hole 32a is formed on the horizontal wall 32.

At the front end of the optical cable 5, a connection fitting 40 is attached to securely connect the front end portion to the optical connector. The attachment of the fitting 40 will be described. When attaching the coupling fitting 40, first, a cylindrical first pipe 45 is inserted between the reinforcing fiber 8 and the two optical fiber wires 6 from the end face side of the optical cable 5 (see FIG. 6). Therefore, the two optical fiber lines 6 are located in the first pipe 45. At this time, the reinforcing fibers 8 are previously exposed from the distal end of the optical cable 5, and the exposed reinforcing fibers 8 are folded on the jacket 7, and
The upper and lower parts are bundled.

Next, the second pipe 41 is
Attach. The second pipe 41 is, as shown in FIG.
The protrusion 42 is formed of a substantially cylindrical member, and has a protrusion 42 in which two upper and lower portions protrude in the outer peripheral direction to form a groove-shaped protrusion space to the outer peripheral side. The second pipe 41 is attached to the optical cable 5 by covering the outer jacket 7 from the front end side of the optical cable 5, but at this time, the second pipe 41 is folded over the outer jacket 7 as described above, and divided into two upper and lower bundles. As shown in FIGS. 5 and 6, the reinforcing fibers 8 thus obtained are put into the groove-shaped projecting spaces of the projecting portions 42, respectively.

Then, with the coupling fittings 40 (ie, the first pipe 45 and the second pipe 41) attached to the distal end of the optical cable 5, as shown in FIG.
Pressing is performed by a press die 50, and the protruding portion 42 of the second pipe 41 is caulked, and the whole is pressed and deformed into a hexagonal column shape. Here, the first pipe 45 is the second pipe 4
The second pipe 41 is press-deformed as shown in the figure, but the first pipe 45 is hardly deformed. Therefore, the jacket 7 and the reinforcing fibers 8 are sandwiched between the first pipe 45 and the second pipe 41, and the coupling fitting 40 is securely coupled to the distal end of the optical cable 5.
Further, since the protruding portion 42 is also pressed and caulked by the die 50, the reinforcing fiber 8 folded and bundled on the jacket 7 is firmly held by the protruding portion 42.

Next, the assembly of the optical connector will be described. As described above, the coupling fitting 40 is attached to the tip of the optical cable 5.
Before the cable is mounted, the cable hood 30 is mounted on the optical cable 5. Further, two optical fiber wires 6 are exposed and extend from the distal end of the optical cable 5 having the coupling fitting 40 attached to the distal end. After attaching the compression springs 35 to the optical fiber wires 6 thus exposed, the ferrule 1 is attached to the distal ends thereof. The ferrule 1 is inserted into the ferrule receiving hole 11a of the ferrule holding portion 11 of the connector case 10 from the rear side and attached as shown in FIG.

The hood portion 3 of the cable hood 30
1, the fitting 40 is inserted into the cable hood 30, and the end of the optical cable 5 is attached to the cable hood 30. At this time, as shown in FIG.
1 is received in the slot 31a of the hood portion 31. In this state, the cable hood 30 is attached to the hood receiving portion 18. At this time, the side wall 3 of the cable hood 30
The guide pin 19 is inserted into the pin guide hole 32a formed in
Is inserted, and the vertical wall 33 enters the guide groove 18b to perform the mounting positioning.

Next, as shown in FIG. 3, the connector cover 20 is mounted on the connector case 10 so as to cover the housing portion 13 and the hood receiving portion 18. At this time, the positioning protrusion 26 of the connector cover 20
Is inserted into the positioning hole 15a of the connector case 10 to perform mounting and positioning. In this state, the bolt 38 is inserted through the bolt holes 16a and 21a, and a nut is screwed into the bolt 38 and fastened, and the connector cover 20 is fixed to the connector case 10.

At this time, as shown in FIG. 4, the cable hood 30 is sandwiched and fixed between the case 10 and the cover 20. Further, the protrusion 42 of the second pipe 41 protrudes outward through the slot 31a of the cable hood 30, and the protrusion 42 is received in the receiving grooves 18c, 28c of the upper and lower housings 10, 20. As a result, the distal end of the optical cable 5 is securely coupled to the optical connector via the coupling fitting 40. Therefore, even if an external force that pulls or twists the optical cable 5 acts on the optical cable 5, the external force is received by the coupling portion, and the external force does not affect the internal optical fiber line 6.

When the connector cover 20 is attached in this manner, the lock lever 23 is located in the lock lever receiving groove 11 of the connector case 10. With the connector cover 20 attached in this manner,
The pressing plate 25 of the connector cover 20 covers the space between the partition wall 14 and the positioning wall 15 from the rear as shown in FIG. 2, and presses the compression spring 35 located in this space from the rear. For this reason, the compression force of the compression spring 35 acts as a force for pressing the ferrule 1 forward, and the ferrule 1 is fixedly held.

[0024]

[Effects of the Invention] As described above, according to the present invention,
First around the inner circumference of the reinforcing fiber so as to surround the optical fiber line.
The pipe member is inserted, the reinforcing fiber exposed from the end of the optical cable is folded back on the jacket member, and the bundle is divided into a plurality of bundles, and the reinforcing fiber thus folded and bundled is folded. The second pipe member is pressed and deformed while crimping the protruding portion so as to be inserted into the groove-shaped protruding space, and the second pipe member deformed in this way is pressed by the optical connector. Since the holding structure is held by the housing, and the distal end of the optical cable is connected to the optical connector, the connecting structure is configured, so that each reinforcing fiber folded and bundled by the swaged protrusion is sandwiched, and A jacket member and a reinforcing fiber are sandwiched between the first and second pipe members. Therefore, when the second pipe member is fixedly held by the connector housing, not only the reinforcing member but also the jacket member can be held by the connector housing. Even when the optical cable is pulled or twisted, these pulling forces, The torsional force is received by the fixing portion, and these forces are not applied to the internal optical fiber line, so that damage to the optical fiber line due to external force and reduction in optical signal transmission efficiency can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a two-core optical connector and an optical cable coupled by a coupling structure according to the present invention.

FIG. 2 is a partial sectional view showing the two-core optical connector.

FIG. 3 is a front view showing an assembled state of the two-core optical connector.

FIG. 4 is a cross-sectional view showing a coupling portion of the two-core optical connector with an optical cable.

FIG. 5 is a front view showing a state where a coupling fitting is attached to the optical cable.

FIG. 6 is a cross-sectional view showing a state in which a coupling fitting is attached to the optical cable.

FIG. 7 is a cross-sectional view showing a state in which the fittings attached to the optical cable are joined by press working.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrule 5 Optical cable 6 Optical fiber wire 7 Jacket 8 Reinforcement fiber 10 Upper connector housing 20 Lower connector housing 30 Cable hood 40 Joint fitting

Claims (1)

(57) [Scope of request for utility model registration] 1. A structure in which at least one optical fiber line is covered with a cylindrical jacket member having a reinforcing fiber on an inner peripheral side, and a distal end portion of an optical cable is coupled to an optical connector. A first pipe member inserted around the optical fiber line from the distal end to the inner peripheral side of the reinforcing fiber, wherein the reinforcing fiber exposed from the distal end of the optical cable is folded back onto the jacket member, and A second pipe member having a plurality of protrusions forming a groove-shaped protrusion space toward the outer peripheral side enters the folded and bundled reinforcing fibers into the groove-like protrusion space. The second pipe member is press-deformed while caulking the protruding portion, and the second part thus press-deformed is attached. The flop member and held by the housing of the optical connector, coupling structure of the optical cable to the distal end portion of the optical cable in the optical connector, characterized in that coupled to the optical connector.