JPS63118103A - Optical fiber cable for energy transmission - Google Patents

Abstract

PURPOSE:To allow a holding member to follow up the elongation of an optical fiber at the time of energy transmission and to prevent unreasonable stress from being applied to the optical fiber by holding an optical fiber cable integrally and making one end side movable together with a holding means. CONSTITUTION:The optical fiber 5 is inserted into a thin metallic tube 8 and both end parts 5a and 5b are held by holding members 9 and 10. The holding member 9 which holds the side of the incidence end 5a of the optical fiber 5 is fixed partially to the metallic tube 8 and the optical fiber 5 is held elastically with specific spring pressure by a pressure member 9a, springs 11a and 11b, and screws 12a and 12b. The holding member 10 also holds the periphery of the projection end 5b of the optical fiber 5 elastically by a pressure member 10a, etc., similarly, but one end of the holding member 10 is a bearing part 10b and easily movable in the axial directions of the optical fiber 5 through a bearing 15 and a slide bearing 16. Consequently, the holding member 10 is made to follow up the thermal expansion of the optical fiber without any trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fiber-optic energy transmission path that requires high energy transmission, such as those used in carbon dioxide laser processing machines.

BACKGROUND OF THE INVENTION Laser processing machines are currently in widespread use for cutting industrial materials such as metals and resins, and for other processing.

Laser processing machines, especially carbon dioxide laser processing machines, use multiple mirrors to guide the laser light from the laser light source to the working position, reflecting the laser light and directing the light to the target position. A so-called mirror joint type light guiding path has been used.

On the other hand, recently, in the field of carbon dioxide laser scalpels, systems using optical fibers as light guide paths for carbon dioxide laser light have become popular due to their ease of use and other advantages.

In the field of laser processing machines, a one-way optical fiber light guide path is desired as it may be able to easily handle three-dimensional processing, which is currently in increasing demand. A suitable light guide path has not been obtained.

Problems that the invention aims to solve The transmission energy of original fibers used in carbon dioxide laser scalpels, etc. is about soW, but in laser processing machines, etc., the energy handled ranges from 5ooW to more than 1KW. When an optical fiber transmits high energy, the optical fiber generates heat due to internal loss of the optical fiber, and the optical fiber stretches due to thermal expansion.

If you fix the optical fiber near both ends with a holding member, etc., the elongation of the optical fiber will be restricted, and unreasonable stress will be applied to the optical fiber, resulting in damage to the optical fiber. , there is a risk of burnout during energy transmission.

Conventionally, for example, Japanese Unexamined Patent Publication No. 57-10
As shown in Japanese Patent No. 4778, one end of an optical fiber is left free so that it can freely expand and contract in the direction of the optical axis, so that no undue stress is applied to the optical fiber.

However, although these methods are effective in that no mechanical stress is applied to the optical fiber, they are particularly useful for optical fibers that must transmit high energy, such as in laser processing machines, where the end face, which is most likely to generate heat, is It was not possible to obtain a high-output energy transmission line because the parts could not be cooled in any way.

Means for Solving the Problems In order to solve these conventional problems, in the present invention, both end faces of the optical fiber are held by a material with good thermal conductivity such as metal, and a holding member is used to prevent the elongation of the optical fiber during energy transmission. This prevents excessive stress from being applied to the optical fiber.

Function In the present invention, one end of the optical fiber is fixed to the optical cable housing the optical fiber by a holding member, and the other end is provided with a holding member configured to follow the optical fiber as it expands and contracts as energy is transmitted. Since the optical fiber is held by a member, the vicinity of the end face of the optical fiber, which tends to generate heat due to the holding member, can be constantly cooled.

EXAMPLE Hereinafter, FIGS. 1 to 4, which show an example of the present invention, will be explained. FIG. 1 is a schematic diagram of an optical fiber one-type carbon dioxide laser processing machine according to the present invention.

Laser light 2 emitted from carbon dioxide laser oscillator 1
is condensed by the condensing lens 3, enters the end face 6a of the optical fiber 6 housed in the optical cable 4, and the optical fiber 6
is transmitted and emitted from the end face 5b. Furthermore, laser light 2
The light is focused by a lens 6 housed within the optical cable 4 and irradiated onto the workpiece 7, where a predetermined process is performed.

In such a carbon dioxide laser processing machine, two-dimensional or three-dimensional processing is performed by connecting an optical cable to an X-Y table, an articulated robot, or the like.

Here, the optical cable according to the present invention will be explained in detail with reference to FIGS. 2 and 3.

The optical fiber 5 is inserted into a thin metal tube 8 made of stainless steel or the like, and both ends 5a and 5b are connected to a holding member 9,
It is held in 1Q. The holding member 9 that holds the incident end 5a side of the optical fiber 6 is partially fixed to the metal tube 8, and as shown in FIG.
The optical fiber 6 is elastically held by screws 12a and 12b with a predetermined spring pressure. Further, the holding member 9 is fixed to the holder 13 with screws 14.

On the other hand, the holding member 10 also has a structure in which the vicinity of the output end 5b of the optical fiber 5 is elastically held by a holding member 10a, etc., but one end of the holding member 10 is
0b, and the optical fiber 6 is connected by a bearing 16 and a slide bearing 16 fixed to the metal tube 8.
The holder 13 can be easily moved in the axial direction of the window by means of a holding screw 18.
Fixed. 19 is a protective cable, one end of which is fixed to the holder 13 with a screw 20, and the other end of which is fixed to the lens 21.
It is fixed with screws 23 to a lens holder 22 that holds the lens. 24 is a screw holding the lens 21, 25 is a bearing 16
This is the fixing screw.

The optical cable according to the present invention has the above-described configuration, and the laser beam 2 emitted from the laser oscillator 1 and focused by the lens 3 enters the input end 6a of the optical fiber 6. Further, the laser beam 2 propagates inside the optical fiber 5, is emitted from the output end 6b, is focused by the lens 21, and is irradiated onto the target workpiece to perform a predetermined process.

At this time, the optical fiber 5 undergoes thermal expansion particularly in the optical axis direction due to heat generation due to internal loss and the like as energy is transmitted. Here, since the output end 5b of the optical fiber 5 is configured to be movable in the optical axis direction together with the holding member 1o by the slide bearing 16, the holding member 1o easily follows thermal expansion of the optical fiber 6. Therefore, no excessive mechanical stress is applied to the optical fiber 6.

However, both end faces sa and 6b of the optical fiber 6, which are most likely to generate heat due to high energy transmission, are always held by holding members 9 and 10 made of a material with good thermal conductivity. Since the generated heat can also be efficiently dissipated, the optical fiber 5 will not melt even during high energy transmission.

FIG. 4 shows another embodiment of the present invention. To explain this, a groove 9b is formed on the outer periphery of the holding member 9, and a hole leading to the capture cable 19 is formed in a part of the groove 9b. 9c is configured.

The holder 13 has a hole 13a communicating with the groove 9b of the holding member 9.
is formed.

On the other hand, one end of a bellows 26 is fixed to the holding member 10, and the other end of the bellows 26 is fixed to the inner surface of the lens holder 22. Furthermore, the lens holder 22 has a hole 2.
2a and a hole 15a is formed in the bearing 15, respectively.

The optical cable shown in Figure 4 has the above-mentioned configuration,
By flowing the cooling fluid from the hole 13a of the holder 13 in the direction of the arrow, the holding members 9 and 10 and the metal tube 8 are cooled, so that the optical fiber 5 can be efficiently cooled over almost its entire length. By using a bellows 26 with a small spring constant, the holding member 1o can be made to follow the thermal expansion of the optical fiber without any problem.

Effects of the Invention As described above, according to the present invention, one of the holding members that hold both end faces of the optical fiber is configured to follow the thermal expansion of the optical fiber, thereby eliminating the need to apply unreasonable stress to the optical fiber. , it is possible to efficiently cool the vicinity of both end faces of the optical fiber, where heat is most likely to be generated during energy transmission.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a carbon dioxide laser processing machine using an optical fiber cable for energy transmission according to an embodiment of the present invention, Fig. 2 is a sectional view of the optical fiber cable, and Fig. 3 is a cross-sectional view of the optical fiber cable. FIG. 4, which is an exploded perspective view of the holding member, is a sectional view of an optical fiber cable for energy transmission in another embodiment of the present invention. 6... Optical fiber, 8... Metal tube, 9.10... Holding member, 16...
・Bearing, 16...Slide bearing.

Claims (2)

[Claims] (1) Providing a holding means for holding both ends of an optical fiber that transmits an energy beam such as a carbon dioxide laser beam,
An optical fiber cable for energy transmission, wherein one end of the optical fiber is integrally held by the holding means with an optical fiber cable housing the optical fiber, and the other end is movable together with the holding means. (2) The optical fiber cable for energy transmission according to claim 1, wherein the optical cable is provided with a cooling means for cooling at least the holding member.