JPH01200210A - Production of aluminum tube incorporating optical fiber unit - Google Patents

Abstract

PURPOSE:To continuously produce an Al tube without defects by subjecting the Al tube to drawing plural times simultaneously with straight take-off to reduce the diameter. CONSTITUTION:An extrusion device 3 is provided with a heat shielding member 8 to prevent the heat from being transmitted to an optical fiber unit A at the time of hot extrusion of an Al tube 16. The Al tube 16 after extrusion is subjected to cold drawing plural times and is hardened thereby, and a required hardness is obtained when the soft Al tube 16 of good extrudability is extruded. Further, the diameter of the Al tube 16 is successively reduced at the time of drawing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an aluminum tube containing an optical fiber unit used in an optical fiber composite overhead ground wire (OPGW) or the like.

[Conventional technology]

Conventionally, the method for manufacturing such an aluminum tube containing an optical fiber unit is to continuously form an aluminum tape into a circular tube shape using forming rolls, and to
The optical fiber unit is housed inside this, and the joints are seam welded using continuous seam welding equipment to create an aluminum tube that houses the optical fiber unit, and the diameter of this aluminum tube is reduced by drawing as necessary. has been done.

(Problem to be solved by the invention) However, with this manufacturing method, it is necessary to perform seam welding stably over a long length, strict process control is required, and welding defects may occur. However, even if the defect was extremely slight, the entire long product would be defective, resulting in poor manufacturing yield.

[Means to solve the problem]

This invention has a heat shielding member provided inside a hollow nipple. When an aluminum tube is continuously extruded using a friction-driven extruder Q, an optical fiber unit is housed inside this aluminum tube in step 6, and then this aluminum tube is pulled out in a straight line and simultaneously subjected to multiple drawing operations. ! By using a method of reducing the diameter of the aluminum tube, the disadvantages of the conventional manufacturing method were solved.

Hereinafter, this invention will be explained in detail based on the drawings.

FIG. 1 shows a manufacturing method suitable for use in the manufacturing method of the present invention.
Accusation? 7, in which reference numeral 1 is an optical fiber transmission section. The optical fiber unit I to sending unit 1 is a well-known filament sending device that sends out a long optical fiber wound around a sending drum 2. The light here? Fiber unit h A refers to an optical fiber core, a unit consisting of multiple optical fiber cores, a cable consisting of this unit, an optical fiber cord, an optical fiber core, or an optical fiber such as an optical fiber core. This is a general term for all transmitters. The optical fiber units 1 to 8 sent out from the optical fiber units 1 to 1 are successively fed into an extrusion device 3 that accommodates the optical fiber units 1 to A in a hot extruded aluminum tube.

This extrusion device 3 is a friction-driven extrusion device or a conflu
This extrusion device is an improved extrusion device called a rubber extrusion device, and as shown in FIG. . The drive wheel 4 has a groove 10 formed on its outer circumferential surface to form a metal cabin 9.
It is designed to rotate in the direction of the arrow in the figure by a drive shaft (not shown). The fixed shiko block 5 is
It has an arcuate inner circumferential surface that circumferentially contacts and engages with the outer circumferential surface of the drive wheel 4, and an extrusion chamber 11 that is continuous with the metal introduction chamber 9 is formed inside thereof. An annular extrusion die 7 is provided at a portion 11h of the extrusion chamber 11, and a hollow nipple 6 is provided at the rear thereof. This hollow nipple 6 consists of a cylindrical part 6a and a 7 flange part 6b. It is fixed to the block 5. A hollow portion of the hollow nipple 6 opens into an optical fiber unit insertion hole 12 formed in the fixed shoe block 5.

Furthermore, a cylindrical heat shielding member 8 is fixed to the inner wall of the hollow portion of the hollow nipple 6 . This heat shielding member 8 is
As shown in Fig. 3, a thin metal tube 14 made of copper alloy, stainless steel, etc. is spirally wound around the outer circumferential surface of a metal vibrator 13 made of copper alloy, stainless steel, etc. with good thermal conductivity. It is configured such that a cooling medium such as cooling water can flow through the thin metal tube 14. This heat shielding member 8 is made of asbestos,
An optical fiber is coaxially attached to the inner wall of the hollow nipple 6 via a heat-resistant heat insulating material 15 such as ceramics, and inserted into the hollow portion of the heat shielding member 8 from the optical fiber unit insertion hole 12 of the fixed shoe block 5. Unit A
The number of L11 people has increased.

In such an extrusion device 3, when a rod-shaped preheated aluminum material B is supplied to the entrance of the metal inlet chamber 9, as the drive wheel 4 rotates, the contact friction resistance between the drive wheel 4 and the aluminum material B increases. Aluminum material B
is sent into the metal introduction chamber 9 and further press-fitted into the extrusion chamber 11. In this state, cooling water or the like is poured into the metal thin tube 14 of the heat shielding member 8, and when the optical fiber unit Δ is inserted into the heat 11ri member 8 through the optical fiber unit insertion hole 12, the extrusion die 7 and the hollow The aluminum tube 16 whose inner and outer diameters are defined by the cylindrical portion 6a of the nipple 6 is continuously extruded, and at the same time, the optical fiber unit 8 is housed within the aluminum tube 16. At this time, the inner diameter of the extruded aluminum tube 16 is considerably larger than the outer diameter of the optical fiber unit A due to the presence of the hollow nipple 6 and the heat shielding member 8.

The aluminum tube 16 containing the optical fiber unit A extruded in this way is then sent to a cooling device 17, where it is cooled for 7Jl, and then passed through a first tube elongation die 17.
After being sent to the
A caterpillar-type pulling machine 19 takes it straight. For cold drawing with a tube drawing die, use a hollow plug and insert optical fiber units 1 to △ into the center hole of the plug. ) can be applied.

The diameter reduction rate of the aluminum tube 16 in the first tube drawing die 18 is approximately 15 to 25%. To remove the aluminum tube 16 during this drawing process, a method is required to remove the aluminum tube 16 without bending it. I can not use it. This is because the diameter of the aluminum tube 16 is reduced by undergoing the widening process, and the running speed of the aluminum tube 16 after the widening process increases, and is the same as the running speed after this increase. This is because the internal optical fiber unit A runs at a high speed, so if the aluminum tube 16 is bent and taken out, the optical fiber unit A will be damaged due to the difference in running speed.

The aluminum tube 16 containing the optical fiber unit Δ taken off by the first caterpillar type take-off machine 19 is then further subjected to cold center processing in the second tube drawing die 2o, and then taken to the second caterpillar-type take-off machine 21. The aluminum tube C containing the optical fiber unit is taken up and rolled onto the winding roll 23 of the winding device @22. Of course, if necessary, the third
It is possible to reduce the diameter of the aluminum tube 16 until it reaches a desired diameter by providing a fourth, fifth, etc. tube drawing die and a caterpillar type take-off machine.

According to such a manufacturing method, since the extrusion device 3 is provided with the heat shielding member 8, the heat during hot extrusion of the aluminum tube 16 is not transmitted to the optical fiber unit 8, and the optical fiber unit Δ will not deteriorate due to heat. In addition, since the extruded aluminum tube A is subjected to cold drawing multiple times, work hardening occurs, and even if a soft aluminum tube 16 with good extrudability is extruded, it cannot be used for optical fiber composite overhead ground wires, etc. It has the necessary hardness for use. Furthermore, since the diameter of the aluminum tube 16 is reduced sequentially, the running speed after the diameter reduction is higher than that during extrusion, and even though the conform type extrusion device 3 is used, productivity is high (2 Of course, the inconveniences caused by conventional welding of the seams of aluminum pipes are also solved.

〔Example〕

A 5US316 stainless steel pipe 13 with a thickness of 0.5s and an outer diameter of 5, and a 5US304 stainless steel T with an outer diameter of 2#
! The A-thin tube 14 was spirally wound and made into a heat shielding member 8 using a rowie ζJ poppy, and this was installed in the hollow mandrel 6 of the extrusion device 3 as shown in FIG. While cooling water is flowing through the thin tube 15, the soft aluminum material B is extruded and the outer diameter is 20.
In order, an aluminum tube 16 with an inner diameter of 18M was extruded, and an optical fiber unit 8 with an outer diameter of 3.0 mm was drawn from the heat shielding member 8. This material was cooled, and then the diameter was continuously reduced using five tube drawing dies and five caterpillar type pulling machines, resulting in an aluminum tube with an outer diameter of 6 r MR 1 and an inner diameter of 4.8.
# Closed.

In this way, the transmission characteristics of the aluminum tube containing the optical fiber unit were the same as the original, and no abnormality was observed.
No pinhole cap defects were observed in the aluminum tube, and it was suitable for use as an optical fiber composite overhead ground wire.

〔Effect of the invention〕

As explained above, the optical fiber unit 1-
The manufacturing method for the aluminum pipe is to install a heat shielding member inside the hollow nipple.)〒1! ! After continuously extruding the aluminum tube using a drive-type extrusion device and storing the optical fiber unit inside the aluminum tube,
This method draws the aluminum tube in a straight line and at the same time performs multiple drawing operations to reduce the diameter of the aluminum tube, so that the long aluminum tube containing the optical fiber unit can be continuously processed without defects and without any defects. It can be manufactured without deteriorating the unit. In addition, since the diameter of the aluminum tube is reduced by drawing, the final aluminum tube containing the optical fiber unit can be manufactured at a faster speed than the extrusion speed of the aluminum tube, resulting in good productivity. The aluminum tube is hardened by hardening and has strength suitable for optical fiber composite overhead ground wires and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a manufacturing device used in the manufacturing method of the present invention, FIG. 2 is a schematic sectional view showing an example of an extrusion device similar to FIG. 1, and FIG. FIG. 2 is a schematic cross-sectional view enlarging the main part of FIG. 2; DESCRIPTION OF SYMBOLS 1... Optical fiber unit delivery part, A... Optical fiber unit 1-13... Extrusion device, 6... Hollow nipple, 8... Heat shielding member, 16... Aluminum tube,
18...First tube drawing die, 19...First caterpillar type pulling machine, 20...Second tube drawing die, 21...
・Second caterpillar type take-up machine, 22... take-up device, C
...Aluminum tube with optical fiber unit.

Claims (1)

[Claims] Using a friction-driven extrusion device equipped with a heat shielding member inside a hollow nipple, an aluminum tube is continuously extruded, an optical fiber unit is housed inside this aluminum tube, and then the aluminum tube is taken out in a straight line and simultaneously extruded. A method for manufacturing an aluminum tube containing an optical fiber unit, characterized by reducing the diameter of the aluminum tube by performing drawing processing multiple times.