JPH03236001A - Fiber cable for energy transmission - Google Patents

Abstract

PURPOSE:To allow the cooling of the incident end face and transmission path of an optical fiber with simple constitution by inserting an optical fiber into a protective tube which allows the incidence of IR energy only on the core part of the optical fiber and introducing a dry gas into this tube. CONSTITUTION:The optical fiber is inserted into the protective tube 4 which allows incidence of the IR energy only on the core part of the optical fiber consisting of the core 1 and clad 2 and the dry gas is introduced from a gas introducing port 5 into this tube. Since the parts exclusive of the core part of the incident end face 7 are shielded in such a manner, the clad 2 and a coating resin 3 on the outer periphery thereof do not generate heat and burn in spite of the incidence of the IR energy of the diameter larger than the core diameter. The damaging of the incident end face 7 is obviated at the time of optical axis alignment. Since the cable is cooled by the dry gas, the cooling of the incident end face 7 and the transmission path is possible and the attachment and detachment of the cable are easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a fiber cable structure used for energy transmission.

[Conventional technology and its problems] When infrared energy is input into a conventional energy transmission fiber cable, it is necessary to prevent heat damage to the infrared energy input end face and to facilitate optical axis alignment with the infrared energy light. The incident diameter of the infrared energy light was made slightly larger than the core diameter. Therefore, there is a problem in that the infrared energy that cannot enter the core generates heat and burns out the coating resin provided on the outer periphery of the energy transmission path, resulting in damage to the energy transmission path.

As a method to prevent this, as shown in FIG.
An energy transmission cable having a cladding 12 and a resin coating 13 on its outer periphery is inserted into the storage tube 14, and an infrared energy shielding material 15 is placed on the incident end side of the core 11.
However, the use of shielding VI15 has the problem of complicating the cable structure. moreover,
There was a problem with poor energy transmission efficiency because the energy density at the time of incidence was low. On the other hand, if the incident diameter of the infrared energy light is made smaller than the core diameter, there is no need for a shielding material and the energy transmission efficiency becomes high, but it is difficult to align the optical axis, and in addition, the heat generation is the most intense, as well as the energy transmission path. The infrared energy input end face had to be forcibly cooled from outside the cable.

In order to solve this problem, cables with a complicated structure at the input end as shown in FIG. 3 are also being considered. That is,
The core glass 11 is inserted into the protective tube 14, and the infrared energy incident side portion of the protective tube 14 is made large in diameter so that the core exposes the incident end surface of the lath 11, and a refrigerant gas inlet 17 and an outlet are provided in the vicinity thereof. 18, and a structure in which a condenser lens 16 is arranged roughly at the end of the protective tube has been proposed. With this structure, when the fiber in the cable is damaged, it is difficult to remove it from the optical system and align the optical axis, and there is a problem that it is not possible to immediately replace it with another cable.

An object of the present invention is to provide a fiber cable for energy transmission with a simple structure that allows infrared energy to be incident only on the core of the fiber at the infrared energy input end face, cool the input end face, and simultaneously cool the energy transmission path. There is a particular thing.

[Means for Solving the Problems 1] In order to achieve the above object, the present invention is such that a fiber having a core-clad structure is inserted into a protection tube into which infrared energy can be incident only on the core portion. The protection tube is located at the infrared energy input end of the cable,
It has a hole that is smaller than the core diameter of the fiber and whose central axis coincides with the fiber.

In the present invention, when infrared energy is input, since the cladding part of the fiber is shielded from the infrared energy from the beginning, the infrared energy is incident only on the core part.
It is also characterized by a structure in which the input end face and the energy transmission path are cooled by dry gas flowing in the length direction of the fiber.

[Function] According to the present invention, since the input end face of the fiber other than the core portion is shielded from infrared energy, even if infrared energy light with a diameter larger than the core diameter is incident, the infrared energy is not transmitted. The clad and the coating resin located on its outer periphery do not generate heat or burn out, and Mm of the incident end surface is not caused when aligning the optical axis. In addition, since the input end face and energy transmission path are cooled by the dry gas flowing in the length direction of the fiber, thermal damage to the input end face and energy transmission path can be suppressed with a simple input end structure, and the cable from the optical system can be 11 will also become easier.

[Example J An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an entrance end view of the cable structure of the embodiment. The fiber has a core diameter of 450 (μm) and a cladding diameter of 550 (μm).
m), and the coating resin diameter was 800 (μm). 1 is core, 2
is the cladding, 3 is the coating resin located on the outer periphery of the cladding, 4
5 is a protection tube such as a stainless steel tube that constitutes a part of the cable, and 5 is a dry gas (cooling medium) inlet. The inner diameter of the stainless steel tube 4 is 50 (μm) larger than the coating resin 3.
A hole 6 of 430 (μm) is opened at the tip. The fiber is fixed with its central axis aligned with the central axis of the stainless steel tube. First, infrared energy light was applied to the incident end face 7 with an incident diameter of 250 (μm) without flowing dry gas through the dry gas inlet 5 . At this time, the incident end surface 7 is 12.2 (
Damaged at an energy density of w/a.

In addition, when the input end face was brought into close contact with the tip of the stainless steel tube and dry gas of 5 (f/giin) was flowed from the dry gas inlet 5 to the energy transmission path with no dry gas flowing to the input end face, the incidence end face 7 is 14.9 (in W/m)
received a II wound at an energy density of .

Next, the entrance end surface 7 is made of stainless steel.
(μm) The fiber was fixed so as to be located at the rear, and a dry gas of 5 (II 2 /In) was flowed from the dry gas inlet 5 to the input end face and the energy transmission path with the dry gas flowing to the input end face. In this case, the incident end face is 42.8 (KW
Even at an energy density of /CI, there was no damage, and the coating resin did not generate heat or burn out. At this time, cooled dry gas may be used. Even if this energy transmission fiber cable is connected and detached from the optical axis of the infrared energy light, even if the infrared energy light is incident! ) The J end face was not damaged at all.

[Effect of the invention] The method of the present invention injects infrared energy only into the core,
Since the input end face and energy transmission path of the fiber are cooled by the dry gas flowing roughly along the length of the fiber, the input end face and energy transmission path of the fiber can be cooled with a simple Kasol structure, and it is also easy to attach and detach from the optical system. It is.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the input end of the energy transmission cable structure of the present invention, and FIGS. 2 and 3 are cross-sectional views of the conventional input end. 1... Core, 2... Clad, 3... Coating resin,
4... Stainless steel tube (protection tube), 5... Dry gas inlet, 6... Hole, 7... Core entrance surface. Non-Oxide Glass Research and Development Co., Ltd.

Claims (1)

[Claims] 1. A fiber cable for energy transmission, characterized in that a fiber having a core-clad structure is inserted into a protection tube that allows infrared energy to enter only the core portion. 2. The fiber cable for energy transmission according to claim 1, wherein the protective tube has a hole at the infrared energy input end of the cable that is smaller than the core diameter of the fiber and whose central axis coincides with the fiber. 3. The fiber cable for energy transmission according to claim 1, wherein the protection tube has a cooling medium inlet in a side wall to cool an infrared energy incident end face. 4. The fiber cable for energy transmission according to claim 1, wherein the protection tube has a cooling medium inlet in a side wall to cool the energy transmission path. 5. The fiber cable for energy transmission according to claim 3 or 4, characterized in that the cooling medium flows in the length direction of the fiber. 6. The fiber cable for energy transmission according to claim 3 or 4, wherein dry gas is used as the cooling medium.