JPS6195307A - Production of optical cable - Google Patents

Abstract

PURPOSE:To prevent the generation of distortion when optical fibers are bent by applying the twists in the left-hand and right-hand directions to an optical unit which is manufactured by delivering continuously a sector provided with grooves in parallel with the axis, inserting the fibers into the grooves and providing retaining winding thereto. CONSTITUTION:The grooved sector 12 having the grooves 14 in parallel with the axis is continuously delivered and the optical fibers 16 are put into the grooves 14. The retaining winding 18 is provided thereonto to manufacture the optical unit 30. The twistes in the left-hand and right-hand directions are applied to the unit 30. The insertion of the fibers 16 into the grooves 14 is thereby made easier and the production is speeded up. Since the unit 30 is twisted after the fibers 16 are inserted into the grooves 14, the grooves 14 are alternated on the inside and the outside and the distortions of the fibers 16 contained in the grooves are offset. Since the unit 30 is twisted in the left- hand and right-hand directions, both sides of the delivery and taking-up are made non-rotating. The execution of the large twisting stage in tandem is thus made possible for added convenience.

Description

DETAILED DESCRIPTION OF THE INVENTION This 5e1 month relates to a method for manufacturing an optical cable having a grooved sector in which an optical fiber is loosely inserted. - In the 5th review, an example of a conventional optical cable with one grooved sector was shown (Japanese Patent Publication No. 58-54362).

There is a grooved kisector 12 around the tension member 10, and the optical fiber 16 is loosely inserted into the groove 14.
A restraining winding 18 is applied thereon, and an outer covering 20 is applied thereon.
This is the structure.

By the way, in this case, kW l 4 is necessarily in the form of a spiral. it is.

1) To give flexibility to the cable.

2) This is to alleviate the strain applied to the optical fiber 16 when the cable is bent.

The problem of 2) distortion mitigation will be explained in more detail as follows.

If the groove 14 were not spiral, but parallel to the axis of the sector 12, as shown in FIG. 6(a), when the sector 12 was bent, the outer groove 14 would be stretched, and the inner groove The groove shrinks, and the optical fiber in the outer 111 is subjected to stretching strain, shortening its rupture life. Additionally, the optical fiber within the inner groove may be compressed, leading to increased optical loss due to buckling.

On the other hand, if the groove 14 has a spiral shape as shown in FIG. and shrinkage cancel each other out. Therefore, the strain on the optical fiber within the premises is also alleviated.

That's why.

However, when such a spiral grooved sector 12 is used, the ninth order becomes a problem.

(1) When making a km sector, a normal extruder will not work, so use a single-turn die type, or use a p-1 turn on both sides of the delivery and winding. It is necessary to take such methods. Therefore, the cost increases accordingly.

(2) In order to align and insert the optical fibers 16 into the helical 4% l 4, it is necessary to rotate them relative to each other, and the control thereof must also be highly accurate;
So compared to putting it in a straight line.

Manufacturing speed drops to a few minutes to tens of minutes.

& ■ 2 AND'' The purpose of the present invention is to provide a method for manufacturing an optical cable that solves the above problems, speeds up the manufacturing process, and does not cause distortions that would cause trouble to the fiber even when subjected to bending.

Sa-yu As shown in ff11 diagram.

(+) Continuously sending out the fiber 15 sectors 12 having grooves parallel to the axis, inserting the optical fiber 16 into the fiber, and applying a restraining winding 18 on the fiber to form the optical unit 30.

(2) After that, a step of twisting the optical unit in the SZ direction.

It is characterized by including.

L Yu Kyou J As shown in "Figure 1", from the delivery ll, the groove 1 parallel to the axis.
4, and the optical fiber 16 is inserted into the groove 14. Since the groove 14 is straight, the optical fiber enters the fiber by simply placing it next to it and passing it through the gold 50.

That's why you don't need a complicated Mug, Sector! 2 can run at high speed.

Then, hold down the optical fiber so that it does not escape from the drop.
The optical unit 30 is constructed by performing the machining 8.

Next, an SZ twisting device 54 is provided past the take-off fi 52, and twists the optical unit 30 alternately in left and right directions.

Thereafter, the cable is made into an M4 size by cutting it out and then covering it with a sheath.

When the optical unit 30 is twisted in the SZ direction in this way, when it is subjected to one bend as in the case of a spiral store, the disease moves alternately between the inside and the outside.

Elongation and contraction cancel each other out.

Also, by twisting Sz alternately, both sides of the feed and 63 picks can be made non-rotatable, which is very convenient.
In particular, as described later, the large twisting process can be performed in tandem, which is very convenient.

The requirements for SZ twisting are as follows.

(1) Giving a twist in the SZ direction means adding a twist and making sure that it remains until later, so plastic or metal that deforms plastically is preferable for the material of sector 12.However, it is preferable to use plastic or metal that deforms plastically. If it is possible to twist with an inert twisting torque, it is possible to prevent untwisting by using a sheath or coating layer on top of the twisting torque. No problem.

(2) The angle of reversal of the SZ twist should be at least ±
180'? ! ! Several times the amount is required.

(3) The pitch of the SZQ turns is desirably set to 2π times or more the bending radius of the cable even for M people, but it can be changed as appropriate depending on the magnitude of the frictional force between the groove and the optical fiber.

(4) Since the reversal pitch has nothing to do with the 6-offsetting effect, it is not very important in terms of characteristics and can be determined in relation to productivity.

(5) If the take-up truss 52 and the take-up 4t56 themselves are reversed, there is no need to add a special SZ twisting device 54.

Next, we will discuss an example where the entire process is carried out in tandem up to the assembly of large twists.

r: fS2 figure”, sending out 3! by rotating it in the direction of the arrow 33, and attaching it to the center member 32 such as the tension member.
The material is fed out while being rotated in a certain direction (for example, in the S direction) (drip rotation of the central axis).

The optical unit 30 twisted in the SZ direction as described above is vertically spun around the center member 32 without any twisting, and the optical unit 30 is twisted in the SZ direction. ,a
The handle a60 is also rotated in the same direction and at the same pitch as the center member 32, as indicated by the arrow 61.

In this way, a cable core 40 having a cross section as shown in FIG. 3 can be obtained.

Note that there are cases in which a large number of optical fibers are placed in the groove, and there are cases in which only one optical fiber is placed in the groove. Furthermore, optical fiber tape may also be inserted.

In the claims, there are 1 mentions of "optical fiber".
It includes the above.

Next, before considering i#, numerical examples such as the pitch of SZ twist H will be shown.

The layer core diameter of the sector unit is D, and the twist pitch is P.
Then, the bending radius R due to the large twist set in that sector is
teeth.

Therefore, the pitch P of the SZ twist of the sector is P≦πD
(1+C-2-?r)3.

Assuming 0m20mm and Psg500mm, p
51080mm At this time, let's temporarily set the reversal angle to 180"
, 380'', then the inversion pitch P is.

P, Tomi P! 10801m (180”)Py
= 2p m2120mm (380@).

"Figure 4" shows a case where the reversal angle is 380°.

Since the sector 12 having 1414 parallel to the (+) axis is continuously sent out, it is easy to insert the optical fiber into the groove, and the manufacturing speed can be increased.

(2) After inserting the fiber into the groove to construct the optical unit, the optical unit is given a twist in the SZ direction.
The groove L4 alternately switches between the inside and the outside, and the distortion of the optical fiber inside is canceled out.

(3) Szt the unit again! ! As mentioned above, send out and Jl! Since both sides of the weave can be made non-rotating, it is convenient to carry out the large twisting process in tandem.

[Brief explanation of drawings]

FIG. 5 and FIG. 2 are explanatory diagrams of different implementation pillars of the present invention. Figure 3 is an explanatory diagram of the cross section of the cable core made by the method shown in Figure 2, and Figure 4 is a diagram of the reversed pitch. FIG. 5 is an explanatory diagram of a conventional optical cable having sectors marked with &. No. 61 is an explanatory diagram when bending a grooved sector, (a
) is for parallel iM, and (b) is for spiral clearing. 12 Sectors with rainbow holes 14 Double grooves 16: Optical fiber 30: Optical unit 32: Central member 40: Cable core SS: SZ twisting device patent applicant Skin Care Core Co., Ltd. Japan? IT news'rt1 story public company

Claims (1)

[Claims] A grooved sector with grooves parallel to the axis is continuously fed out, an optical fiber is inserted into the groove, and an optical fiber is wrapped around it to create an optical unit.
A method for manufacturing an optical cable, characterized by imparting directional twist.