JP2000292662A - Optical fiber cable for yag laser transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify structure, to facilitate manufacture, to reduce a cost, and to shorten delivery. SOLUTION: This cable is provided with a coated optical fiber 1, a stainless spiral tube 2 inserted penetratedly with the fiber 1, and a flexible hose 3 inserted penetratedly with the metal tube 2. A base 4 is provided to receive the metal tube 2 to be fixed and to fix the hose 3. The base 4 has a port member 4e for introducing a purging fluid into its inner space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable having a simple structure, and more particularly, but not exclusively, to an optical fiber cable for transmitting a high-power laser for processing over a relatively short distance. About Bull.

[0002]

2. Description of the Related Art Some optical fiber cables for telecommunications have a configuration similar to that of a cabtire cable of electric wire, and in one example, a core supporting member having a plurality of grooves having a tension member at the center. Arrange a plurality of optical fiber cores in order, and use tape + middle sheath,
There is a copper dimantel and a PVC outer sheath, which are coated in this order, so that a plurality of optical fiber cores can be arranged neatly. An optical fiber cable having such a structure is resistant to pulling, dragging and weathering, but is expensive. If there is no stock, the delivery waiting period is long, especially for short orders, waiting for orders of the same specification to accumulate, or an extremely expensive estimate.

An optical fiber as a method of transmitting a high power light beam for processing such as a YAG laser from, for example, a laser light source to a laser processing head, usually has a laser processing head which is a robot arm. It is flexible and can transmit a light beam in a free direction because it moves while being supported by a robot. The power of the YAG laser used for welding and cutting is 1
As large as ~ 6 KW, damage to the optical fiber in the transmission path is extremely dangerous. An optical fiber core wire for transmitting a high power optical beam is obtained by coating a cladding on the outer side of a core (usually about 0.6 to 1.0 mm) with a resin.

[0004]

By the way, the optical fiber core is made of pure quartz, and is easily broken. If the light beam is irregularly reflected due to a scratch or the like, heat is generated and burned at that portion, causing an external leakage accident of the beam. I do. Therefore, the optical fiber is passed through the protective tube. The Applicant manufactures a cable for a high power light beam by passing an optical fiber through a stainless steel tube or a stainless steel spiral tube. The small diameter thin stainless steel tube is flexible and can be bent. Spiral tubes are more flexible and can be bent with a smaller radius of curvature than ordinary small-diameter thin-walled round tubes when they have the same diameter. ing. However, even if the optical fiber core is protected in this way, it may be bent below the allowable bending radius of the optical fiber core wire, and there are problems in pull resistance, drag resistance, weather resistance, and the like. Optical fiber cable for telecommunication as described above
Although the use of a cable structure can solve these problems, it is extremely expensive for high power optical beam transmission despite its very short distance and short transmission. However, problems such as a very late delivery are likely to occur.

It is a first object of the present invention to provide an optical fiber cable for transmitting a YAG laser having a simple structure, a second object to facilitate manufacture, and to provide an inexpensive optical fiber cable. For the purpose of 3,
A fourth object is to provide various specifications in a short delivery time.

[0006]

Means for Solving the Problems (1) In view of the above, the Y of the present invention
The optical fiber cable for AG laser transmission is an optical fiber core (1), a flexible metal tube through which the optical fiber core (1) passes.
(2) and a flexible hose through which the flexible metal tube (2) passes
(3).

According to this, the flexible hose (3) withstands the tensile force and prevents the flexible metal tube (2) from bending with a small radius against the bending force applied to the cable. . Flexible hose (3)
Can be used for air pressure, hydraulic pressure, gas, water, hot water, etc. according to the cable installation environment, installation length, allowable bending radius of optical fiber cable, etc. It is. These flexible hoses (3) have high tensile strength and high weather resistance. In addition to these tensile strength and weather resistance, there are various types such as flexibility (bending radius), material, hose structure, wall thickness, and inner and outer diameters. It is cheap. Therefore, the optical fiber cable of the present invention can be manufactured easily, inexpensively and promptly.

The inner diameter of the flexible hose (3) through which the metal spiral tube (2) is passed through the optical fiber core (1) is used to prevent the metal spiral tube (2) from moving inside and avoiding damage such as rubbing. It is desirable to be as small as possible. Metal spiral tube
The technology for passing the optical fiber (1) through (2) and the metal spiral tube (2) through the flexible hose (3) are described in
The one disclosed in Japanese Patent No. 6923 and Japanese Patent No. 2642337 can be applied.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (2) The flexible metal tube (2) is a spiral tube. According to this, the flexibility of the cable is high, and the cable can be easily mounted on a meandering path. Further, it is suitable for a usage mode in which a bending force is repeatedly applied to a cable, such as when the laser processing head is connected to a laser processing head and the laser processing head is driven by a robot arm. The flexible hose (3) prevents excessive extension of the spiral tube (2) and also prevents excessive bending. (3) Further, the end of the flexible metal tube (2) is inserted inside, and the base itself is inserted into the end of the flexible hose (3).
(4) A metal tube fixing means (4d) for fixing the end of the flexible metal tube (2) to the base (4), and the end of the flexible hose (3) to the base (4). An optical fiber cable having a hose fixing means (5) for fixing to an optical fiber. (4) The base (4) has a tube end fixture (4b) inserted through the end of the flexible metal tube (2) and through which the optical fiber core (1) penetrates. The means (4d) is a screw in which the flexible metal pipe (2) is screwed to the base (4) and the flexible metal pipe (2) is crimped to the pipe end fixture (4b). (5) The base (4) has a port member (4e) for receiving a fluid in its internal space.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0011]

FIG. 1 shows one end of an optical fiber cable for transmitting a YAG laser according to an embodiment of the present invention, and FIG. 2 shows a cross section taken along the line II-II of the cable. This optical fiber cable is attached to a laser processing head (not shown) supported by a robot arm (not shown) by a high power YAG laser for welding and cutting.
(1 to 6 Kw), and when assembled to a laser oscillator, a laser beam emitted from a focus adjusting convex lens 6 in the oscillator passes through an optical fiber core 1 and a laser processing head. It is led to.

The optical fiber 1 is made of a quartz core and a cladding on the surface of the optical fiber, and the surface of the fiber is coated with a resin through an adhesive layer, and penetrates the stainless steel spiral tube 2. The stainless steel spiral tube 2 has a cross section of S
A stainless steel strip of a shape (self-shaped) is spirally wound into a tube and passed through a synthetic resin sheath (thin tube), and penetrates the Tetron blade hose 3. The tetron blade hose 3 is formed by integrally joining three members by sandwiching a net tube knitted with tetron yarn between an inner rubber tube and an outer rubber tube.

The tip of the stainless steel spiral tube 2 is inserted into a base 4 a of the base 4. At the tip of the tube 2, the stem of a button-shaped tube end fixture 4b with a stem centered on an optical fiber insertion hole is inserted. The spiral tube 2 is crushed and crimped to the tube end fixture 4b by screwing a set screw 4d screwed into the base 4a. There are four set screws 4d distributed at a 90-degree pitch around one fiber core. The pipe end fixture 4b is inserted into the male screw hole of the base 4a, and is pressed by the female screw end of the cap 4c of the base 4 screwed into the male screw hole.
a and the cap 4c.

At the tip of the base 4a, a crest (inter-groove projection) between a plurality of ring-shaped grooves, which resists removal from the hose 3, is provided.
These grooved ends are inserted into the hose 3. At this end, the hose 3 is tightened and compressed by a hose band 3. As a result, the hose 3 is firmly fixed to the base 4a of the base 4. At the time of arranging the cable, holding the hose 3 allows the cable to be routed. The bending radius at this time is determined by the bending force applied to the cable and the bending strength of the spiral tube 2 and the hose 3. The hose 3 prevents excessive elongation of the spiral tube 2 when a tensile force is applied to the cable,
Excessive bending of the spiral tube 2 when a bending force is applied is prevented.

The cap 4c of the base 4 has an air supply port 4e.
Are attached, and the air supply tube 4f connected to the port 4e is held by a stopper 4e. When transmitting a YAG laser, a dry (water-free) non-oxidizing gas is fed into the air supply tube 4f, and the port 4e.
Through the fiber 4 through the through hole of the optical fiber core, and partly squirts toward the lens 6 to gas-purge the space around the distal end of the optical fiber core 1 and the space in front of it. . A part enters the spiral tube 2 through the optical fiber through-hole of the tube end fixture 4b,
Head to the other end of the cable.

The optical fiber cable shown in FIGS. 1 and 2 has a simple structure, and the hose 3 is available in various specifications immediately and inexpensively on the market. Although the arrangement length is short, it is suitable for an optical fiber cable for high-power laser transmission for laser processing in which the length and required specifications vary.

A plurality of optical fiber-containing flexible tubes 2 can be passed through one tube, and a plurality of optical fiber cores 1 can be passed through one flexible tube 2. .
Further, in the above-described embodiment, the hose 3 composed of one mesh tube and two rubber layers sandwiching the mesh tube is used. However, when the tensile strength may be low, the hose of the single rubber tube is used. It can also be used. Conversely, when higher strength or higher weather resistance is required, a multi-layer hose in which a two-layer or three-layer mesh tube or cloth winding is sandwiched between three or four rubber layers is used. The degree of freedom of these choices, especially the availability from the market, is extremely high, the cable can be easily manufactured, and the cable can be provided at low cost and with good timing.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

[Explanation of symbols]

1: optical fiber core wire 2: stainless steel spiral tube (flexible metal tube) 3: hose 4: base 4e: port 4g: air supply tube

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Okuyama 7-6-1, Higashi Narashino, Narashino City, Chiba Prefecture F-term in the Equipment Division, Nippon Steel Welding Industry Co., Ltd. (Reference) 2H050 AD11 BB02Q BB02S BB26R BC11

Claims (2)

[Claims] An optical fiber cable for YAG laser transmission, comprising: an optical fiber core, a flexible metal tube through which the optical fiber passes, and a flexible hose through which the flexible metal tube passes. −
Bull. 2. The optical fiber cable for transmitting a YAG laser according to claim 1, wherein the flexible metal tube is a spiral tube or a manual tube.