JPS6243605A - Waveguide for carbon dioxide laser light - Google Patents

Abstract

PURPOSE:To prevent temperature from rising locally and transmission loss from increasing, and to protect an internal wall and improve reliability and safety for a long period by providing a holder which holds a lens at both dies of a metallic hollow waveguide which has an external cooling means and providing an intake and an outlet nozzle and a detour hole for dry gas to the entrance-side and exit-side holders. CONSTITUTION:A cooling medium is flowed through a pipe 2 surrounding the outer periphery of the metallic hollow waveguide 1 spirally to cool the waveguide. The dry gas which flows in an intake 8 provided behind a condenser lens 6 held by the entrance-side holder 3 passes through the waveguide 1 and the detour hole 10 surrounding a lens 7 held by the exit-side holder 4 to flow out of a nozzle 9 at the tip. Water is therefore prevented from sticking on the internal wall of the waveguide 1 and dust is also prevented from entering the waveguide 1 and sticking on the lenses 6 and 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a waveguide for carbon dioxide laser light, and particularly to a waveguide for high power carbon dioxide laser light that is useful for industrial processing such as welding, cutting, and heat treatment. .

[Prior Art] Flexible carbon dioxide laser waveguides aimed at practical use can be roughly divided into: infrared waveguides that use an F4 body as a core, and hollow waveguides that use air as a transmission medium. It can be divided into

Among these, metal hollow waveguides, including waveguides with dielectrics inside, are particularly suitable for input power transmission because they have no reflection at the output end face, have high thermal conductivity, and have high cooling efficiency. ing.

[Problems to be Solved by the Invention] In a hollow waveguide, the entire exterior of the waveguide can be cooled with water or the like. However, in this case, the temperature of the inner wall of the waveguide becomes below the dew point, and even a small amount of water on the inner wall of the waveguide may become tinged with moisture. The absorption coefficient of water at a wavelength of 106 m (577 m) is close to losm, and even a small amount of water causes a rapid increase in transmission loss. This increase in transmission loss due to water is eliminated by evaporation of the water, but In the case of power, it becomes a high-loss waveguide for a relatively long time.Also, when transmitting power of 100W or more, the temperature locally rises instantaneously to nearly 100℃.Such a local temperature rise The higher the power, the more dangerous it becomes, leading to damage to the inner wall of the waveguide.

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For example, in a metal hollow waveguide that is made of a material that is usually called a dielectric conductor, there is a risk of thermal runaway due to the instantaneous temperature increase. Runaways are more likely to occur. Furthermore, in a dielectric-incorporated metal hollow waveguide, it has been theoretically shown that the closer the refractive index of the internal dielectric material is to f2, the lower the ta loss waveguide becomes. Generally deliquescent. Therefore, even if only the outside of the four wave paths is cooled, moisture adhering to the inner wall causes unevenness on the inner wall, degrading the transmission characteristics.

The present invention solves the above-mentioned problems, and the local temperature hg
The purpose of the present invention is to provide a waveguide for high-power carbon dioxide laser light, which prevents the increase in transmission loss and protects the inner wall of the hollow waveguide, and improves long-term reliability and safety.

[Means for Solving the Problems] The carbon dioxide laser light waveguide of the present invention has a hollow metal waveguide having an external cooler F, and a holder for holding a lens at each side. The holder on the input side is provided with dry gas inflow holes at 10 positions between the end of the metal hollow waveguide and the holder on the output side. The device is characterized in that a nozzle for discharging dry scum is provided at a position opposite to the lens, and a detour hole is provided for guiding the dry scum toward the nozzle, bypassing the lens.

In the present invention, by ejecting dry gas +' passing through the metal hollow waveguide from the output l, internal heat is released to the outside through φ, and moisture is deposited on the inner wall of the waveguide. By selecting the type of drying gas, it is possible to prevent dust from entering the waveguide or from adhering to the exit lens. It can also be used as an auxiliary gas to increase the processing efficiency of materials.

It is easy to use air at room temperature as the gas to flow into the hollow region of the waveguide, but in addition to air, CO2
, 0U, N2, Ar, etc. are used. However, in a metal hollow waveguide, if 02 or air is introduced, the transmission loss will increase due to oxidation of the inner wall of the waveguide, so it is not appropriate to use 02 or air. However, in a metal hollow waveguide with a dielectric inside, Depending on the purpose of use, any of the gases listed in L can be used.

[Example] An embodiment of the present invention will be described with reference to FIG.

1 is a hollow waveguide, 2 is a pipe for transporting a cooling medium (for example, water), 3 is an input side holder, 4 is an output side holder,
Further, 5 is a carbon dioxide laser oscillator.

The hollow waveguide 1 is surrounded by a pipe 2 in a spiral shape, and is cooled by a cooling medium flowing through the pipe 2.

A condensing lens 6 is held in the incident side holder 3,
An inflow hole 8 through which dry gas flows is provided between the lens 6 and the end of the hollow waveguide l. The inflow hole 8 is provided to allow a flow of dry gas equal to or greater than that of the hollow waveguide 1.

A condensing lens 7 is held on the output side holder 4, and a nozzle 9 for discharging dry gas is provided at the tip. Further, the exit side holder 4 is provided with a detour hole 1O for guiding the drying gas toward the nozzle 9, bypassing the lens 7. The detour hole 10 has a dry gas flow rate equal to that of the hollow waveguide l.
is equal to or greater than 1, and the nozzle 9
The drying gas flow rate is set to be less than 1 in the hollow waveguide.

When dry gas with a temperature higher than the dew point flows in from the inflow hole 8 of the input side holder 3, the dry gas advances from the input side of the hollow waveguide to the output side, passes through the detour hole 10 of the output side holder 4, and enters the nozzle 9. As a result, moisture can be prevented from adhering to the inner wall of the hollow waveguide 1, and dust can also be prevented from entering the hollow waveguide 1 and adhering to the lens.

Also, by changing the type of drying gas, the flow rate, the pressure, etc., it is possible to increase the addition I', the force)I: -)ζ
Konaro.

FIG. 2 is an explanatory diagram of an example of the song of Honkomei.

Same as in Fig. 1 - Designated parts are given the same reference numerals, vibrator 2
The figures are omitted.

In this embodiment, the amount of dry dregs consumed is reduced by causing the dry dregs to flow out from the output nozzle 9 only when the laser beam is directed into the hollow waveguide 1.

11 is an optical shutter, 112 is a switching valve, 13 is a return vibe, 1.1 is a cooling device, 15 is a circulation l; pump, 1 [3 is to a gas cylinder.

When the laser beam is blocked by the optical shutter 11, the dry gas is returned to the inlet hole 8 via the return vibrator 13, the cooling device rIi 14, and the circulation pump 15 by the switching valve 12 that operates in tandem with the optical shutter 11. . optical shutter 1
When 1 is a leap, the switching valve 12 directs the drying gas to the nozzle 9.
It is supposed to be leaked from.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent a local temperature rise and an increase in transmission time due to moisture in the hollow waveguide. In particular, in a metal hollow waveguide with a dielectric inside, it is possible to protect the inner wall and suppress the temperature of the dielectric to obtain a high-output waveguide for carbon dioxide dregs lasers with excellent reliability. .

In addition, the debris passing through the hollow waveguide is removed from the exit nozzle by 11
By making it 0, it is possible to prevent dust from entering from the workpiece and improve processing efficiency.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment 19+1 of the present invention, and FIG. 2 is an explanatory diagram of another embodiment of the present invention. 1: Hollow waveguide, 2: Cooling medium axial pipe, 3: Incident side holder, 4: Output side holder, 6.7: Lens,
8: Inflow hole, 9: Nozzle, 10: Detour hole. Agent Patent Attorney Fujio Sato Procedure No. 12.13 ] Case Report 1989 Patent Application No. 183291
No. 2 Name of invention Waveguide for carbon dioxide laser light 3 Famous representative for correction Hiroharu Hashimoto 4th representative Publication 00 Location 2-1-2 Marunouchi, Chiyoda-ku, Tokyo @ Drawings subject to correction (Full drawings) ). The details of the amendment are as shown in the attached sheet. Attached phylum catalog drawing - 1 copy or more

Claims (1)

[Claims] (1) A holder for holding a lens is provided on the input side and output side of the metal hollow waveguide having an external cooling means, and the holder on the input side has a holder that holds a lens between the lens and the end of the metal hollow waveguide. An inflow hole for dry gas is provided at the position, and a nozzle for outflowing the dry gas is provided at the position opposite to the hollow metal waveguide on the exit side holder, and
A waveguide for carbon dioxide laser light, characterized in that it is provided with a detour hole that guides dry gas toward a nozzle by bypassing a lens.