JPH0255305A - Side injection type hollow waveguide - Google Patents

Abstract

PURPOSE:To attain welding or the like for the inwall of a thin pipe without using a complex external mirror by making the projection ends of a hollow waveguide asymmetrical about its center axis and making the wall of the waveguide unparallel about the center axis. CONSTITUTION:A part of the projection part of a nickel hollow waveguide with 100mum thickness coated with a germanium thin film 1 with 0.5mum thickness on its inside is cut off to form the unparallel projection end inclined by 45 deg. from the center axis L. Thereby, the course of a gaseous CO2 laser beam 3 can be changed by a reflection plate 4 formed on the projection end. Consequently, the welding, heat processing, etc., of the inwall of a thin SUS pipe can be attained by the gaseous CO2 laser beam using such kind of the side projection type hollow waveguide 6 without requiring an ordinarily used complex external mirror consisting of ZnSe or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a side-emitting type hollow waveguide, and particularly to a side-emitting type hollow waveguide applied to processing equipment and the like.

[Prior Art] Currently, processing and heat treatment using carbon dioxide laser light are contrary to many industrial fields, including welding, cutting, marking, and the like. The output of these lights ranges from several watts to several kilowatts, and processing machines are becoming more sophisticated and accurate in order to enable a variety of higher quality applications. By the way, the biggest factor limiting the performance of current carbon dioxide laser processing machines is the laser beam transmission method. For transmission of carbon dioxide laser light, Zn
A spatial propagation method using reflection by a mirror such as Se is used. However, this propagation method requires a mirror to change the course of the laser beam, so extremely complex optical axis control technology is required to guide the laser beam from the laser transmitter to the workpiece and perform high-precision machining. become indispensable.

Therefore, at present, independent movable R-tops are provided for both the laser beam and the workpiece, and high-precision and high-speed processing is made possible by controlling them.

However, since this method requires a complicated optical axis control section, there is a problem in that the cost increases.

Therefore, a flexibility transmission method is being researched as a more functional and economical transmission method. This flexibility transmission system includes, for example, an infrared fiber such as KR3-5 and a hollow waveguide having an air core. Among these, infrared fibers are unsuitable for large-capacity optical energy transmission because of reflections at the fiber end faces. Furthermore, this infrared fiber is also used as a laser scalpel that uses about several watts, but problems such as deterioration over time have arisen.

On the other hand, the hollow waveguide method is expected to be used as a highly flexible, large-capacity optical energy transmission path.

Such a flexible hollow waveguide is a transmission line that confines optical energy within a hollow region having air as a core and transmits it in any direction. Examples of flexible hollow waveguides include metal hollow waveguides, glass hollow waveguides, and dielectric-incorporated hollow waveguides. Among these, a hollow waveguide with a dielectric interior has been reported to have a transmission loss of 0.35 dB/m.

Therefore, by using these hollow waveguides, high functionality and high precision processing can be realized at low cost without requiring a plurality of mirrors and complicated optical axis control unlike the spatial propagation method.

[Problems to be Solved by the Invention] However, when a conventional hollow waveguide is used as a light energy transmission line, the laser beam is irradiated only onto a plane perpendicular to the optical axis of the transmission line at the output end. In other words, it was not possible to perform side processing of narrow areas such as heat treatment of the inner wall of a pipe.

SUMMARY OF THE INVENTION Therefore, an object of the present invention was to provide a side-emitting type hollow waveguide with excellent flexibility that can irradiate optical energy to the inner wall of a narrow space such as Pi-1. It's about doing.

[Means for Solving the Problems] As a means for solving the above problems, the present invention provides a method in which the aperture surface at the output end of a hollow waveguide for transmitting optical energy is asymmetrical with respect to the central axis of the hollow waveguide. The hollow waveguide is open, and part or all of the waveguide wall at the output end is formed non-parallel to the central axis of the hollow waveguide. In this preferred embodiment, the output end of the hollow waveguide is formed such that the light energy irradiating portion of the waveguide wall is formed in a concave shape so as to be non-parallel to the central axis of the hollow waveguide. One in which the light energy irradiation part of the waveguide wall at the output end of the waveguide is formed in a convex shape, one in which the light energy irradiation part on the waveguide wall at the output end of the hollow waveguide is formed in a flat plate shape; A cooling medium is passed through the optical energy on the output end waveguide wall, the irradiation part is formed of many irregular irregularities, and the back side of the optical energy irradiation part on the output end waveguide wall of the hollow waveguide. Some have cooling passages.

Effect] The present invention is characterized in that the aperture surface at the output end of a hollow waveguide that transmits optical energy is processed to be asymmetrical with respect to the central axis of the hollow waveguide, and furthermore, part or all of the hollow waveguide is made hollow. By bending the waveguide so that it is non-parallel to the central axis, the light energy transmitted through the hollow waveguide is reflected by the reflective surface and irradiated to the side of the hollow waveguide.

In addition, since the tip m() of the hollow waveguide is processed to form a laser beam reflection part, it is extremely compact and also enables heat treatment of the inner wall of a narrow pipe whose inner diameter is about the same as the outer diameter of the hollow waveguide. do.

Furthermore, by making the reflecting surface of the light energy reflecting section concave to provide light condensing properties, it becomes possible to process a narrower range with higher energy density.

On the other hand, if the shape of the reflecting surface of the light energy irradiation part is made convex to disperse the laser beam, it becomes possible to process the material over a wide range with low energy density.

Furthermore, in the case where the reflecting surface of the light energy irradiation section is shaped like a flat plate, it is possible to perform heat treatment parallel to the irradiated surface.

Furthermore, by irradiating the reflective surface with a laser beam while forming a large number of irregularities, it becomes possible to perform processing with low energy density.

Therefore, by selecting the shape of the reflecting surface in this manner, it is possible to select the processing effect to be imparted to the workpiece.

In addition, in the present invention, there is a concern about temperature rise due to loss at the reflective surface at the tip of the waveguide, but in the case of optical energy transmission of several watts to several tens of watts, it is necessary to It is sufficient to flow the assist gas. And as the transmission power increases,
Heat generation on the reflective surface will increase and there is a risk of destruction of the reflective surface.

In this case, by providing a cooling passage through which a cooling medium passes on the opposite side of the reflective surface, water cooling, air cooling, etc. may be performed as necessary.

[Example] Hereinafter, the side-emitting hollow waveguide of the present invention will be described based on the illustrated example.

FIG. 1 is a plan view of the output part showing the first embodiment of the side-emitting type hollow waveguide according to the present invention. 10
A part of the output part of the 0 μm nickel hollow waveguide 2 is shaved off to make the germanium thin film-incorporated nickel hollow waveguide 2 into a flat plate, which is tilted at an angle of 45° with respect to the central axis of the nickel hollow waveguide 2. In the case of the present hollow waveguide configured in this manner, the course of the carbon dioxide laser beam 3 can be changed to the side by the reflection plate 4 at the emission part.

Figure 2 shows the output part of the side-emitting hollow waveguide from behind.

This is a view. In this hollow waveguide, a flexible pipe 5 for flowing cooling water is attached to the back surface of the reflection plate 4.
The heat generated when the carbon dioxide laser beam 3 is reflected by the reflection plate 4 can be efficiently removed by the flexible pipe 5.

Therefore, in this hollow waveguide, by efficiently removing the generated heat, it becomes possible to control and select the processing effect of light energy.

Furthermore, FIG. 3 is a schematic diagram of welding the inner wall of a SUS pipe using a carbon dioxide gas laser beam using the side-emitting hollow waveguide of the present invention. In this inner wall welding of the SUS pipe, a nickel hollow waveguide 6 with a germanium thin film interior is coupled to an axial flow type carbon dioxide laser oscillator 9.

In welding the inner wall of this SUS vibe, the nickel hollow waveguide 6 is inserted into the curved pipe, and then the carbon dioxide laser beam 3 is irradiated onto the part to be processed.

The carbon dioxide laser oscillator 9 is provided with a gas inlet 10 through which assist gas such as nitrogen or argon flows. When the nickel hollow waveguide 6 is introduced and the workpiece is welded, cooling water is allowed to flow through the pipe 5 shown in FIG. This is performed while flowing an assist gas such as nitrogen or argon into the nickel hollow waveguide 6.

Therefore, when performing main welding, the output end is bent and a hollow waveguide with a reflective surface that reflects light energy in all directions is used to weld small-diameter inner walls without the need for an external mirror such as Zn5e. It becomes possible.

Next, a second embodiment will be described with reference to FIG. 4. In this hollow waveguide, the output end of the germanium thin film-incorporated nickel hollow waveguide 16 is connected to the nickel hollow waveguide 1
The shape of the reflection plate 15 of the optical energy irradiation part of the waveguide wall is formed into a concave shape so as to be non-parallel to the central axis of the waveguide wall. Since the reflecting surface is thus formed in a concave shape, the carbon dioxide laser beam 11 emitted from the nickel hollow waveguide 16 can be focused.

In the irradiated area 12, since the carbon dioxide laser beam 11 is focused by the reflector 1, it is possible to irradiate the area with light having a smaller beam size than the beam emitted from a normal hollow waveguide without using a lens.

Furthermore, in this hollow waveguide, the emission part is formed in a concave shape and the scattering preventing cover part 13 is provided, so that scattering of the laser light from the germanium thin film-incorporated nickel hollow waveguide 16 can be prevented. can. Therefore, the hollow waveguide shown in FIG. 4 can be used to process a narrow range with high energy density.

Further, the optical energy irradiating portion 15 of the output waveguide wall of the nickel hollow waveguide can be formed in a convex shape instead of a concave shape. In this case, scattering of the laser light from the nickel hollow waveguide 16 is facilitated by providing an open part (not shown) for promoting scattering. The carbon dioxide laser light is scattered by the convex light energy irradiation section 15 of the output waveguide wall and the release section for promoting scattering, and the carbon dioxide laser light is dispersed in the irradiated section 12 . Therefore, the present hollow waveguide is suitable for processing a wide range of interconnections at low energy density.

In addition, in the nine hollow waveguides, the optical energy irradiation part 15 on the output waveguide wall of the germanium thin film-incorporated nickel hollow waveguide can be formed into a flat plate shape instead of a convex or concave shape. It becomes easy to irradiate a surface perpendicular to the direction with the carbon dioxide laser beam. That is, according to this hollow waveguide, when processing a surface perpendicular to the optical energy transmission direction, the laser beam can be irradiated in parallel from the reflective surface of the flat optical energy irradiation section 15, and the pipe surface can be irradiated with laser light in parallel. Heat treatment can be easily performed.

The light energy irradiation part does not necessarily have to be formed as a continuous surface as described above, but can be formed with many irregular irregularities, for example, and this is the third embodiment of the present invention. In this hollow waveguide, by forming a large number of irregular irregularities (not shown) in the optical energy irradiation part on the output end waveguide wall, the irradiated surface can be This makes it easier to scatter the carbon dioxide laser light. As will be explained with reference to FIG.
In this hollow waveguide, the light energy irradiation section 15 is formed with an uneven surface instead of a convex or concave shape, and the carbon dioxide laser beam is dispersed on this uneven surface. Therefore, according to this hollow waveguide, by scattering carbon dioxide laser light from the uneven surface of the light energy irradiation part 15 to the irradiated surface and heat-treating the inner wall of the pipe, an even but uniform processed surface can be obtained. can be obtained.

[Effects of the Invention] As described above, according to the present invention, it becomes possible to emit the energy of carbon dioxide laser light to a plane parallel to the transmission direction. That is, in the present invention, by bending the output end of the hollow waveguide and providing a reflective surface that reflects the optical energy to the side, a mirror of 0/8 of the inner diameter of the small diameter pipe can be It becomes possible to perform contacting, heat treatment, etc.

In addition, by selecting the shape and surface condition of the reflective surface at the output end of the hollow waveguide to be formed, and by providing a cooling pipe on the back side, the generated heat can be efficiently removed and the processing efficiency of light energy can be controlled and It can be possible to choose.

[Brief explanation of the drawing]

1 is a cross-sectional view of the output end showing the first embodiment of the curved hollow waveguide manufactured according to the present invention, FIG. 2 is a view of the output section of the curved hollow waveguide seen from behind, and FIG. 3 4 is a schematic diagram of welding the inner wall of an SUS pipe by carbon dioxide laser light using the curved hollow waveguide of the present invention, and FIG. 4 is a diagram showing a second embodiment of the present invention. In the figure, numeral 2 is a hollow waveguide, 15 is a light energy irradiation part, 16 is a hollow waveguide, and 20 is a hollow waveguide.

Claims (6)

[Claims] 1. The opening surface at the output end of the hollow waveguide that transmits optical energy is opened asymmetrically with respect to the central axis of the hollow waveguide, and further, a part or all of the waveguide wall at the output end is connected to the hollow waveguide. A side-emitting hollow waveguide characterized by being formed non-parallel to the central axis of the waveguide. 2. The side according to claim 1, wherein the output end of the hollow waveguide has a light energy irradiating portion of the waveguide wall formed in a concave shape so as to be non-parallel to the central axis of the hollow waveguide. Projection type hollow waveguide. 3. 3. The side-emitting type hollow waveguide according to claim 1, wherein the light energy irradiation portion of the output end waveguide wall of the hollow waveguide is formed in a convex shape. 4. Claim 1 characterized in that the optical energy irradiation section on the output end waveguide wall of the hollow waveguide is formed into a flat plate shape.
and the side-emitting hollow waveguide according to 2. 5. 3. The side-emitting type hollow waveguide according to claim 1, wherein the optical energy irradiation portion on the output end waveguide wall of the hollow waveguide is formed of a large number of irregular irregularities. 6. 6. The side-emitting type hollow waveguide according to claim 1, further comprising a cooling passage through which a cooling medium passes, provided on the back surface of the optical energy irradiation section on the output end waveguide wall of the hollow waveguide.