JPH02207580A - Carbon dioxide gas laser - Google Patents

Abstract

PURPOSE:To reduce the generation probability of arc discharge, to prevent gas from being deteriorated and to make it possible to obtain high output, high efficiency and a long lifetime by a method wherein a first opening part to correspond to the outlet of a gas flow path and a second opening part to correspond to the inlet of the gas flow path are formed in a wind tunnel and the first and second opening parts are respectively installed in the upper part and the lower part in a container. CONSTITUTION:A wind tunnel 20 is provided with two opening parts of first and second opening parts 21 and 22, the first opening part 21 to correspond to the outlet of a gas flow path is installed in the upper part in a gas container 1 and the second opening part 22 to correspond to the inlet of the gas flow path is installed in the lower part in the container 1. A gas flow 16, which is generated by a fan 9, is made to flow in the tunnel 20 in a laminar flow and after feeding gas to a discharge part, which is constituted of glow discharge electrodes 2a and 2b, the gas flow 16 is released in the upper space in the container 1 through the first opening part 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a high-output carbon dioxide laser device used for cutting and welding metals, isotope separation, and the like.

(Prior Art) Carbon dioxide laser devices are widely used for cutting and welding metals because they can provide high efficiency and high output. Recently, attention has also been paid to the application of carbon isotope separation using light of a specific wavelength emitted by a carbon dioxide laser, as well as to the isotope separation of other atoms.

In the above-mentioned carbon dioxide laser device, a glow discharge is generated in a laser medium gas containing a mixture of CO2 (carbon dioxide), N2 (nitrogen gas), and He (helium gas), and CO2 is excited by this discharge. , to obtain laser light.

By the way, due to such glow discharge, some CO2
It is known that the gas deteriorates and the laser output decreases due to the decomposition of molecules and generation of CO and O2.

Furthermore, it is known that when the gas deteriorates, stable glow discharge cannot be maintained and arc discharge is more likely to occur. Since such arc discharge has high density and high temperature, it not only makes laser oscillation impossible, but also damages the electrodes, further accelerates gas deterioration, and significantly shortens the life of the carbon dioxide laser device. was.

Therefore, as a countermeasure against the above-mentioned gas deterioration, a method as shown in FIG. 7 has conventionally been taken.

That is, glow discharge electrodes 2a and 2b are arranged facing each other in the gas container 1, and the glow discharge electrode 2a is fixed to a conductor 3a and connected to a lead wire 4 at the same time. Further, the lead wire 4 is kept insulated from the gas container 1 by a bushing 5, is led out of the gas container 1, and is connected to a pulse power source (not shown). On the other hand, glow discharge electrode 2b
is fixed to the conductor 3b and connected to the ground potential by a lead wire (not shown). Furthermore, capacitor 6
a, 6 b s Gap 7 is a device that performs preliminary ionization to generate glow discharge. Further, a wind tunnel 8 is installed in the gas container 1, and a gas flow is generated by a blower fan 9, thereby discharging the glow discharge electrode 2a.

The structure is such that fresh gas can be supplied to the discharge section formed by 2b. The wind tunnel 8 is configured so that the gas flow generated by the blower fan 9 passes through the discharge section and returns to the blower fan 9 again so that the gas flowing therein becomes a laminar flow. Furthermore, in the gas container 1,
A gas regenerator 10 is connected via a gas pipe 11, and is configured to be able to regenerate degraded gas.

According to research conducted by the present applicants, arc discharge caused by gas deterioration is not caused by 02 generated by decomposition of CO2, but by 03 generated by further decomposition of 02 (
It has been found that this is caused by ozone gas). That is, 0
3 has an extremely large electron adsorption coefficient compared to other gases, and quickly absorbs (adsorbs) the electrons generated during glow discharge.
Since heavy negative ions with low mobility are quickly formed, it is considered that a small amount of 03 makes it impossible to maintain a stable glow discharge, and the discharge shifts to an arc discharge. Also, although 03 is an active gas, it is quite stable,
It is known that it takes a considerable amount of time to disappear and become 02.

(Problems to be Solved by the Invention) However, the conventional carbon dioxide laser device as shown in FIG. 7 has the following problems to be solved. That is, the gas that has deteriorated in the discharge section formed by the glow discharge electrodes 2a and 2b quickly goes around the inside of the wind tunnel 8 and returns to the discharge section again within a short period of time. Therefore, the 03 generated in the discharge section does not disappear and returns to the discharge section again. In this case, it is possible to remove 03 using the gas regenerator 10 provided in the gas container 1, but in order to process the gas flow rate comparable to the gas flow generated by the blower fan 9 using the gas regenerator 10, , an extremely large gas regenerator is required. Furthermore, this problem becomes more serious as the laser output increases.

In particular, pulsed carbon dioxide lasers (TEMA), in which the pressure of the laser medium gas is made higher than atmospheric pressure, have recently attracted attention and are being developed in order to increase laser oscillation efficiency, but glow discharge is unstable under high gas pressure. Even if a very small amount of 03 is present, arc discharge will occur. Therefore, in such an apparatus, it is practically impossible to remove 03 using a gas regenerator.

The present invention was proposed to eliminate the above-mentioned drawbacks, and its purpose is to provide a carbon dioxide laser device with high output, high efficiency, and long life, which reduces the probability of occurrence of arc discharge and prevents gas deterioration. It's about doing.

[Structure of the Invention] (Means for Solving the Problem) The invention as claimed in claim 1 is such that a wind tunnel, which is a gas flow path including a blower fan, is installed in a container in which a discharge electrode is installed, and a wind tunnel is formed by the discharge electrode. In a carbon dioxide laser device that supplies laser gas to a discharge part, the wind tunnel is formed with a first opening corresponding to an outlet of the gas flow path and a second opening corresponding to an entrance of the gas flow path, and the first opening corresponds to the inlet of the gas flow path. is located at the top of the container, and the second opening is located at the bottom of the container.

Further, the invention according to claim 2 is characterized in that a solid whose main component is carbon is disposed within the container in which the discharge electrode is installed.

(Function) According to the carbon dioxide laser device according to claim 1, the gas reaches the lower part of the container by releasing the gas into the upper part of the container from the first opening which is the outlet of the gas flow provided in the wind tunnel. 03 can be made to disappear naturally by then.

Furthermore, according to the carbon dioxide laser device according to claim 2,
By disposing a solid whose main component is carbon inside the container, 03 can be quickly converted to 02, and 03, which causes arc discharge, can be effectively removed.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to FIGS. 1 to 6. Incidentally, the same members as those of the conventional type shown in FIG. 7 are given the same reference numerals, and the description thereof will be omitted.

■First Embodiment In this embodiment, as shown in FIG. The second opening 22 corresponding to the inlet of the gas flow path is installed at the bottom of the gas container 1. The gas flow 16 generated by the blower fan 9 flows in the wind tunnel 20 as a laminar flow, and after supplying the gas to the discharge section composed of the glow discharge electrodes 2a and 2b, the gas flow 16 flows through the first opening 21. It is configured to be discharged into the upper space within the gas container 1.

In the carbon dioxide laser device of this embodiment having such a configuration, the high-temperature gas released into the gas container from the first opening 21 of the wind tunnel 20 is gradually cooled in the gas container 1 while being slowly cooled. It moves to the lower part of the gas container 1, and when it reaches the second opening 22 of the wind tunnel 20, it is sucked into the wind tunnel 20 again.

In this way, the gas flow rate inside the gas container 1 can be made extremely slow compared to the gas flow rate inside the wind tunnel, and
Since the high temperature gas heated by glow discharge tends to stagnate in the upper part of gas container 1, the gases that have experienced glow discharge move to the lower part of gas container 1 in the order in which they have experienced glow discharge. Therefore, it takes a long time for the gas that has experienced glow discharge to return to the discharge section again, and 03 tends to disappear naturally. In addition, the surface areas of the various structures installed inside the gas container 1 are quite large, and there are many opportunities to come into contact with these surfaces.
Active 03 is easily converted to 02 by the action of the solid surface. As a result, the gas sent into the discharge section by the blower fan can be a gas that does not contain 03.

The research results of the present applicant showing the above-mentioned effects are shown in FIG. That is, FIG. 2 is a diagram showing the occurrence of arc discharge in a pulsed carbon dioxide laser device that applies pulsed voltage at regular time intervals to obtain pulsed laser output, and the horizontal axis represents the total number of pulsed voltages applied, that is, the total number of The cumulative number of arc discharges that occurred is plotted on the vertical axis. Note that the horizontal axis is a compressed scale compared to the vertical axis. Further, in this experiment, a gas regenerator was not used, and the gas was sealed in the gas container 1. Further, the gas used had a standard composition of CO2:N2:He=1:1:8.

In FIG. 2, curve A is the result when the conventional carbon dioxide laser device shown in FIG. 7 is used, and curve B is the result when the carbon dioxide laser device of this embodiment shown in FIG. 1 is used. It is. In curve B, it can be seen that the incidence of arc discharge is considerably reduced, and gas deterioration due to arc discharge is small, so that the life of the gas is lengthened.

In this way, according to this embodiment, 03 is effectively removed,
Since arc discharge can be prevented, damage to the electrodes can also be reduced, and a longer life, higher efficiency, and higher output of the carbon dioxide laser device can be realized.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and generally, solids containing carbon as a main component, such as activated carbon,
Because it has the effect of quickly converting 03 to 02, the third
As shown in FIGS. 5 to 5, by installing the activated carbon 30 at an appropriate location where a gas flow is generated, 03 can be effectively removed, which is more effective. That is, FIG. 3 shows activated carbon 30 installed near the first opening 21 of wind tunnel 20, FIG. 4 shows activated carbon 30 coated on the inner wall of gas container 1, and FIG. The figure shows activated carbon 30 installed in the center of a gas container 1. Note that activated carbon may be coated not only on the inner wall of the gas container 1 shown in FIG. 4 but also on the surfaces of various structures disposed within the gas container 1.

Second Embodiment In this embodiment, as shown in FIG. 6, activated carbon 30 is disposed within a conventionally used wind tunnel 8.

Also in the carbon dioxide laser device of this embodiment having such a configuration, 03 is quickly reduced to 0 by the action of the activated carbon 30.
2, the incidence of arc discharge can be effectively reduced.

[Effects of the Invention] As described above, according to the present invention, the wind tunnel, which is the gas flow path disposed in the container, has a first opening corresponding to the outlet of the gas flow path and an inlet of the gas flow path. The first opening is placed at the top of the container and the second opening is placed at the bottom of the container, or carbon is placed in the container in which the discharge electrode is installed. By simply disposing a solid material as a main component, it is possible to provide a carbon dioxide laser device with high output, high efficiency, and long life, which reduces the probability of arc discharge occurrence and prevents gas deterioration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a first embodiment of the carbon dioxide laser device of the present invention, FIG. 2 is a diagram showing the operation of the carbon dioxide laser device shown in FIG. 1, and FIGS. 3 to 5 are FIG. 6 is a sectional view showing another embodiment of the present invention, FIG. 6 is a sectional view showing a second embodiment of the invention, and FIG. 7 is a sectional view showing the main parts of a conventional carbon dioxide laser device. 1... Gas container, 2a, 2b... Glow discharge electrode,
3a, 3b...Conductor, 4...Lead wire, 5...Bushing, 5a, 5b...Capacitor, 7...Gap, 8...Wind tunnel, 9...Blower fan, 10.・・・
Gas regenerator, 11... Gas pipe, 16.17...
Gas flow, 20... Wind tunnel, 21... First opening, 2
2... Second opening, 30... Activated carbon. i-ne-shiryo-kuro-t (Figure 2 Figure Figure Figure Figure Figure Figure

Claims (2)

[Claims] (1) In a carbon dioxide laser device in which a wind tunnel, which is a gas flow path including a blower fan, is installed in a container in which a discharge electrode is installed, and a laser gas is supplied to a discharge section formed by the discharge electrode, a gas flow is provided in the wind tunnel. a first opening corresponding to the exit of the road;
Carbonic acid, characterized in that a second opening corresponding to the entrance of the gas flow path is formed, the first opening is installed at the top of the container, and the second opening is installed at the bottom of the container. Gas laser equipment. (2) A carbon dioxide laser device characterized in that a solid whose main component is carbon is placed in a container in which a discharge electrode is installed.