JPS606274A - Production of metallic tube - Google Patents

Abstract

PURPOSE:To obtain a metallic tube which is thoroughly hard over the entire part by delivering a hard metallic tape, forming transversely and successively the tape into a circular shape and welding the butt ends thereof then reducing once the tube with a roller die or die by tandem rolling. CONSTITUTION:While an optical fiber 1 is delivered from a reel 2, a hard metallic tape 3 such as hard Al delivered from a reel 4 is fed through a slitter 5 to a forming unit 6 and while the fiber 1 is housed into the tape 3 formed successively to a semi-circular shape, the tape 3 is rounded to a circular tubular shape. The butt parts of the tape 3 are welded by a torch 7. The metallic tube which cointains the optical fiber and is subjected to welding is passed through a roller die or die 8 and is once reduced to a prescribed size, by which the weld zone is hardened again. The metallic tube which is relatively thin-walled and small-sized and is thoroughly hard over the entire part is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a metal tube that is relatively thin-walled and has a small diameter, and has improved mechanical strength, by rolling a metal tape and welding the mating ends thereof.

Recently, it has become clear that optical fiber cables can transmit large amounts of information, have low loss, are non-inductive, and are insulating materials.
Various cables incorporating this optical fiber have been considered. In such cases, the metal tube that protects the optical fiber is manufactured entirely from metal tape, without using extrusion, and welding the mating ends is an excellent method for obtaining a thin-walled, small-diameter metal tube. recognized as a means.

This method is also commonly used when, for example, a communication line other than an optical fiber is inserted into a metal tube and combined with other power lines or control lines.

In order to realize such a method, although it is generally called a metal tape, in reality it is customary to use a soft metal tape for the subsequent forming action, and the use of a hard metal tape is completely unthinkable. It wasn't.

The present invention was made in view of this situation, and the present invention is
The invention is a method for manufacturing a metal tube, which is characterized by feeding a hard metal tape, sequentially shaping it into a circular shape in the width direction, and welding the mating ends. Use the welding side! <By making the overall strength of the part, that is, almost the metal tube, compared to soft metal tape,
The second invention is a hard metal tube all-roller die W breaker manufactured as described above, which is capable of more fully mechanically protecting a filament such as an optical fiber cable inserted into the interior. The area is reduced to the desired diameter by simply reducing the diameter 1 once at This provides greater mechanical protection for the striatum.

The present invention will be described below with reference to the drawings. The figure shows a method for manufacturing a metal tube with all optical fibers built in. The optical fiber 1 is fed out from all reels 2, while the hard metal tape 3, such as aluminum, is fed out from all reels 4.
It is sent through a slitter 5 to a forming unit 6, where the hard metal tape 3 is formed into a semicircular shape.
While storing the optical fiber tV, it is gradually rolled into a circular tube shape, and when it leaves the forming unit 6, the mating ends of the metal tape 3 are welded with a welding torch 7. At this stage, only the welded area is soft, but the rest of the tube is hard, making it much stronger mechanically than conventional metal tubes made by rolling and welding soft metal tape.

Next, after welding has been completed as described above, the diameter is reduced to a predetermined size in one round of area reduction using a metal tube metal roller die or die 8 with built-in optical fibers.

That is, when using the roller die 8, whereas conventional area reduction using dies and plugs is multi-stage area reduction,
This shortens the process and reduces costs.Furthermore, by making the welded part hard again through this surface reduction process, the internal optical 7 eyeper is protected entirely by a hard metal tube. Become. In the figure, 9 is an eddy current flaw detection device, 10 is a caterpillar traction device, and the product is wound onto a winding drum 11.

Next, examples of the present invention in which all hard aluminum tape, hard aluminum alloy tape, hard copper tape, and hard stainless steel tape are used will be described.

1050 stipulated in Example LJ Ding S H4000
3- All of the equivalent hard cotton At tapes were formed into a circular tube as described above, an optical cable was inserted and the first seam was welded, and a tape was further reduced by 30% using a roller die in tandem. Two types of At tubes containing optical fibers were manufactured.

The mechanical strength and electrical properties of these At tubes were investigated and are shown in Table 1.

Example 2. Hard aluminum (A/) alloy tape (component: Mg
O, 3-0,6Jii%, Si, 0.45-0.65
% by weight, PeO, residual At or less than 3 f%), two types of optical fiber-containing 4-fibers were used: one welded in the same manner as in Example 1, and one whose area was reduced by 25% after welding. All the At alloy tubes were manufactured and their mechanical strength and electrical properties were investigated and the results are shown in Table 2.

Example 3. Using hard copper (Ou) tape, two types of optical fiber-embedded OuIW gold were manufactured: one welded in the same manner as in Example 1, and one with a 20% reduction in area after welding. The strength was investigated and is as shown in Table 3.

Table 3 Example 4 Two types of optical fiber stainless steel tubes, one welded using hard stainless steel tape (SU8 304) in the same manner as in Example 1, and the other with 10% area reduction after welding. Table 4 shows the mechanical strength of these materials.

7- As can be seen from the above examples, the present invention uses a hard metal tape to construct the entire metal pipe, so that even if it is simply welded, it is possible to obtain a metal pipe that has almost the same mechanical strength as the base tape. Furthermore, by forming it once with a roller die or die, it is possible to reduce the area to almost the desired outer diameter, and in this way, the softened welded part is work-hardened again, making it a perfect hard metal/zobe. As a result, it is possible to obtain a product with excellent mechanical strength, and it is expected to reduce costs due to its ease of processing. A long metal tube can be provided that can be protected.

[Brief explanation of drawings]

The figure is a schematic process diagram showing an embodiment of the present invention. 1...Optical fiber 2...Reel 3...Hard metal tape 4...Reel 5...Slitter 6...Pooring double knit 7...Welding torch 8...Roller die 9...・Eddy current flaw detection device 8-1O... Caterpillar traction device representative Patent attorney Mamoru Takeuchi

Claims (2)

[Claims] (1) A method for manufacturing a metal tube, which comprises feeding a hard metal tape, sequentially shaping it into a circle in the width direction, and welding the mating ends. (2) A hard metal tape is fed out, the width direction of the tape is sequentially formed into a circular shape, the mating ends are welded, and the area is reduced once using a tandem roller die or die. Method of manufacturing tubes.