JPS6035041B2 - fiber optic cable connector - Google Patents

Description

[Detailed description of the invention] [Industrial application field] INDUSTRIAL APPLICATION This invention is utilized for an optical fiber cable for communications.

The present invention is an optical fiber that connects optical fiber cables.
Regarding the structure of the connector. [Background of the Invention] FIG. 1 is a diagram showing the structure of an optical fiber cable in which the connector of the present invention is used.

FIG. 1a is a sectional view, and FIG. 1b is an exploded side view of the terminal. In FIG. 1, a fiber wire 1 is coated with nylon or the like to form a fiber 2, and a plastic fiber 3 is coated on the outside of the fiber 2.
It is a structure covered with a PVC jacket 4 with . The plastic fiber 3 acts as a tensile strength member and is designed to have a tensile strength of 100k9 or more.

This plastic fiber 3 also protects the fiber 2 against lateral pressure. The fiber 2 is thin, for example, with a diameter of 125 m, and when connecting an optical fiber cable, the fiber 2 is first connected by a known method.

The connector structure in question here is plastic fiber 3
It is a structure for transmitting the tension transmitted to the other side of the connection. FIG. 2 is a diagram showing a conventional structure.

Connector. In the lug 5, the fiber 2 is already mechanically held. The section of plastic fiber 3 is connected to the terminal end 6 of the connector plug housing part by screwing the hood 8 through the pooper part 7. All the tensile force of the optical fiber cable is received by the hood 8,
The fiber is well protected. [Problems to be Solved by the Invention] However, in this conventional structure, the tip of the plastic fiber 3 is held between the tapered part 7 and the inside of the terminal end 6. It has been found that the plastic fiber 3 slips at this sandwiched portion.

When tests using this conventional structure were repeated, the tapered part 7 and the terminal end 6 were strongly tightened, and the plastic fiber 3
When fixed without slipping, the tip of the tapered part 7 acts as a knife edge on the plastic fiber 3, and when a strong tensile force is applied to the cable, the knife edge breaks the plastic fiber 3. It was observed. Therefore, in this conventional structure, the tensile strength is practically limited to 10k9 times.

On the other hand, it is said that optical fiber cables for communication require a tensile strength of 20k9 or more for installation work and other purposes, and this structure is not yet fully satisfactory. The present invention is an improvement on this problem, and an object of the present invention is to provide a fiber cable connector that has a high tensile strength and requires a small number of man-hours for connection work.

[Means for solving the problem] The present invention attaches the plastic fibers of the optical fiber cable between the connector plug exterior part and the sleeve, fixes them using adhesive, and secures the plastic fibers of the optical fiber cable between the connector plug side end of the sleeve. A flange portion is provided in the connector plug exterior component, and the end boundary surface of the connector plug exterior component is shaped to face the end of the flange portion, and the plastic fiber is disposed between the end of the flange portion and the end boundary surface. It is characterized by a structure in which the tip is sandwiched.

Example An example structure will be explained using the drawings.

FIG. 3 is a sectional view showing the structure of the first embodiment of the present invention.
2 is fiber, 3 is plastic fiber, 4 is PVC
It is the outer covering. Reference numeral 9 is a connector plug exterior part, 10 is a sleeve, and 11 is a hood. Although the structure of the plug portion on the right side of the figure is omitted in this figure, the fiber 2 is connected and mechanically held within the connector plug (not shown) by a known structure. The plastic fibers 3 are loosened radially at the ends and are arranged uniformly along the outer periphery of the terminal end 12 of the cylindrical plug exterior part 9.

The sleeve 10 has an inner diameter slightly larger than the outer diameter of the terminal end 12. By inserting the sleeve 10 into the terminal end 12, the plastic fiber 3 is sandwiched therebetween. Here, one of the features of the structure of the present invention is that when inserting this sleeve 10, adhesive 1 is applied to the plastic fiber 3.
3 is dropped, and the plastic fibers 3 adhere to the inner surface of the sleeve 10 and the outer surface of the terminal end 12.

After this, the hood 11 is inserted and the connector exterior part 9
It is screwed into the threaded part of. FIG. 4 is a cross-sectional structural diagram after assembly.

The plastic fiber 3 is sandwiched between the sleeve 10 and the terminal end 12 and fixed with an adhesive 13. Reference numeral 5 is a connector plug. Another feature of the present invention is that the tip 3' of the plastic fiber 3 is sandwiched between the flange 15 provided on the sleeve 10 and the boundary surface 14 at the end of the exterior part, so that the hood 11 is This part is strongly pressed when screwed in.

As a result of conducting various tests on this structure, it was discovered that if the plastic fibers 3 move while the adhesive 13 is acting, the adhesive 13 will not work properly, and this was the idea. . By providing a structure in which the tip end 3' of the plastic fiber 3 is sandwiched between the flange portion 15 and the boundary surface 14, there is no need to keep the cable stationary during the time required for the adhesive 13 to harden, and the cable is not held still during this time. You will be able to move around and perform the following tasks. In other words, it takes a considerable amount of time for the adhesive to harden, and if the part to be hardened moves during this time, the adhesive will not work effectively, but this structure is suitable for applications where particularly strong tensile forces are applied, such as when laying cables. Unless otherwise specified, you can move on to the next step before the adhesive hardens. This greatly streamlines the assembly process. FIG. 5 is a diagram showing the results of a tensile strength test using the structure of the above example.

The horizontal axis indicates the tensile load applied to the cable, and the vertical axis indicates the elongation (%) of the plastic fiber. The rupture was approximately 50k9 weight,
It can be seen that it can sufficiently withstand a tensile load of 20k9 weight. In the above example, epoxy resin was used as the adhesive, but
Various adhesives that work on plastics and metals can be used.

In the above example, all the peripheral structural parts for attaching and fixing the plastic fibers were cylindrical in shape with a circular cross section perpendicular to the axis, but this cross section was not necessarily circular and could be in various polygonal shapes. can also be implemented in the same way.

Although the above embodiment does not refer to the specific structure of the connector plug 5, the connector plug 5 may be connected to another cable or attached to a fixed device. You can.

It is also possible to implement the structure of the present invention symmetrically around the connector plug 5. In this case, the structure of the connector plug 5 is simplified. The connector plug 5, its exterior parts 9, sleeve 10, hood 11, etc. are preferably formed of a metal material, but may also be formed of a plastic material.

A concept similar to the present invention can also be applied to a connector for a multi-core optical fiber cable.

[Effects of the Invention] The effects of the present invention are listed below.

'1) Since the plastic fibers can be uniformly adhesively fixed on the outer periphery of the terminal end, each fiber acts equally on the tensile force, improving tensile strength. '2) By using adhesive, there is no slippage between the plastic fiber and the connector.

[3} Since there is no part that acts like a knife on the plastic fibers, the plastic fibers will not be damaged within the connector.

(41) The structure is simple, the number of parts is small, and the number of assembly steps is small.

'5} Since each part has a simple shape, it is easy to process the parts.

[6] Even though adhesive is used, there is no need to interrupt the cable assembly work while the adhesive hardens, resulting in high work efficiency.

As a result of various tests, it was confirmed that the cable tensile strength of the connector portion of the connector of the present invention was 20k9 times or more, and it was found to be stable for a long period of time.

The present invention is used for contacts of optical communication cables that are buried underground and used for a long period of time, and its effects are remarkable.

[Brief explanation of the drawing]

Figure 1 is a structural diagram of an optical fiber cable, a is a cross-sectional view,
b is a side view, Fig. 2 is a structural diagram of a conventional connector, Fig. 3 is an exploded structural diagram of the first embodiment of the present invention, Fig. 4 is an assembled structural diagram of the same, and Fig. 5 is a structural diagram of the device according to the embodiment of the present invention. A diagram showing test results. 1... Fiber wire, 2... Fiber, 3.・・・． -Plastic fiber, 4...Outer sheath, 5...Connector plug, 9...Connector plug exterior parts, 10...Sleeve, 1
DESCRIPTION OF SYMBOLS 1...Hood, 12...Terminal part, 13 Adhesive, 14...Boundary surface, 15...Flange part, 18...Hood. Garden 1 drawing 2 drawings rare tree 4 drawings 5 drawings

Claims (1)

[Claims] 1. In an optical fiber cable connector having a plastic fiber acting as a tensile strength body on the outer periphery of the optical fiber, the end of the plastic fiber is slightly closer to the outer circumferential surface of the end 12 of the connector plug exterior part and slightly smaller than this outer circumferential surface. It has a structure in which a hood 11 is fixed to the inner circumferential surface of a sleeve 10 having a large inner diameter through an adhesive, and is covered with a hood 11 which is screwed onto the connector plug exterior part from the outside of the sleeve. A flange portion 15 is provided at the end of the connector plug 10 on the connector plug side, and the end boundary surface 14 of the connector plug exterior part is connected to the tip of the plastic fiber between the end of the flange portion 15 and the end boundary surface. An optical fiber cable connector characterized by a structure in which 3' is inserted.