JPH02251187A - Co2 gas laser oscillator - Google Patents

Abstract

PURPOSE:To increase the area of heat dissipation, and to add a cooling means freely by projecting the heat-dissipating section of a heat pipe to the outside of an oscillator. CONSTITUTION:Discharge pins 2 are implanted to mutual opposed surfaces at the center of an upper half circle section and a pair of upper and lower electrodes 3 at an interval are extended in long size in the axial direction and an air blower 4 is installed in the axial direction to a lower half circle section in a cylindrical body 1 brought to the state of low pressure in a laser oscillator. The electrodes 3 and the air blower 4 are partitioned by a parting plate 5, and an arcuate hood 6 is mounted from the upstream-side opening section of a laser gas flow to the clearance section of the electrodes 3. Several heat exchangers 9 of heat pipes 11 with heat-receiving fins 10 are arrayed to a heat- receiving section on the parting plate side of the hood 6, the heat-dissipating sections of the heat exchangers are penetrated through the end wall 1 of the cylindrical body 1 and projected to the outside, and radiating fins 12 are fixed to the heat-dissipating sections. Accordingly, the heat-dissipating sections of the heat pipes are projected to the outside, thus improving the efficiency of heat exchange by scaling up the radiating fins and adding a cooling means.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a CO□ gas laser oscillator with an improved heat exchanger for cooling the laser gas.

Conventional technology To oscillate laser light, a glow discharge is generated between the electrodes of an oscillator and excitation energy is injected into the laser gas, but only about 10% of the energy is extracted as laser output, so the discharge energy cannot be extracted as laser output. Most of the remaining energy turns into heat and increases the temperature of the laser gas, and this temperature increase further reduces the laser oscillation efficiency, repeating a vicious cycle. For this reason, in a three-axis orthogonal laser oscillator, the laser gas is
The laser gas is circulated in the chamber at a high speed of about 0 m/see, and a fin-and-tube heat exchanger is installed in this circulation path to remove heat from the laser gas and lower the temperature of the laser gas to obtain the desired laser output. is being done.

Problems to be Solved by the Invention One way to lower the temperature of the laser gas is to increase the heat exchange capacity of the heat exchanger and quickly remove the generated heat.In the case of a fin-and-tube heat exchanger, the heat radiation area is increased. Or the number of tubes will be increased. Another way to lower the temperature of the laser gas is to use a powerful blower by increasing the gas flow rate and minimizing the time during which the laser scum is exposed to glow discharge in the discharge space and the temperature is transmitted to the laser gas. .

If the former method is used, there will be a contradiction in that the number of obstacles to the flow of the laser gas will increase, the resistance to the flow will increase, and the flow velocity of the laser gas will decrease.

If the latter is used, the temperature of the laser gas will rise due to heat generated by the compressive work of the blower, and the blower will become larger, making it difficult to downsize the oscillator.

The present invention was made in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a heat exchanger with a large heat exchange capacity without increasing the resistance to the flow of laser gas. The present invention aims to provide a CO□ gas laser oscillator.

Means for Solving the Problems In order to achieve the above-mentioned objects, the present invention uses a heat vibrator as a heat exchanger, and the heat radiation part of the heat pipe is taken out outside the oscillator. Alternatively, the heat dissipation section is placed at a position iδ other than the laser gas flow path.

The laser gas is forced to circulate, and its temperature rises due to the remaining energy that does not contribute to the excitation of the energy injected between the electrodes, and the heat is absorbed by the heat receiving part of the heat vibrator.
The wick inside the pipe carries the heat to the heat dissipation section and dissipates it.

The heat of the laser gas is efficiently removed by the circulation of the cooled wick, keeping the laser gas temperature low.

Embodiments will be described below with reference to FIGS. 1 and 2. The laser oscillator has a cylindrical body 1 in a low-pressure state, and a discharge pin 2 is disposed in the center of the upper half of the body 41U on mutually opposing surfaces, and a pair of upper and lower electrodes 3 with a corner between them extend long in the axial direction. An axially long blower 4 is provided inside the lower half. The electrode 3 and the blower 4 are separated by a partition plate 5, and the laser gas flow is controlled by a partition plate 5.
- An arc-shaped hood 6 is provided from the flow-side space 1 to the gap between the electrodes 3. Further, a funnel-shaped guide tube 7 is provided from the downstream opening of the laser gas flow of the partition plate 5 to the front surface of the blower 4.
An arcuate hood 8 is provided extending from the electrode 3 to the entrance of the guide tube 7. On the partition plate side of the hood 6, several heat exchangers 9 of heat pipes 11 with heat receiving fins 10 are arranged in place of the fin-and-tube type heat exchanger in the heat receiving part, and the heat radiating part is arranged on the end wall of the cylinder body 1. A heat dissipation fin 12 is fixed to the heat dissipation portion of the heat dissipation portion. The space between the heat pipe 11 and the cylindrical end wall 1a is made airtight by an O-ring 13. In addition, several heat exchangers 9 of heat pipes 11 with fins are similarly arranged in the heat receiving part on the exit side of the hood 8, and the heat radiating part with heat radiating fins 12 is arranged on the end wall 1a.
The penetrating portion that protrudes to the outside through is made airtight by an O-ring. Then, the electrode 3 is placed in the direction perpendicular to the laser gas flow.
At the end of the gap, there is a laser beam bending mirror 12 and a total reflection mirror 13.
, a partial reflecting mirror 14 serving as an output window is provided. Note that if the heat receiving section of the heat receiving part 11 has sufficient heat exchange capacity, it is not necessarily necessary to provide heat receiving fins, but it is preferable to provide them because the efficiency will be improved. Furthermore, since the heat dissipation section protrudes outside the cylinder, it is also possible to increase the heat dissipation efficiency by adding a forced cooling fan and a cold water cooling device. It is also possible to place the heat dissipation section in a location other than the laser gas flow path within the cylinder, but in this case the heat dissipation section is more limited.

With this structure, the laser gas in the low-pressure cylinder 1 flows in the direction of the arrow by the blower 4, passes between the heat pipes 11, is guided to the hood 6, passes through the gap between the electrodes 3, and is guided to the hood 8. A forced circulation flow passes between the heat pipes 11 and returns to the blower 4 by the guide tube 7. Electrode 3
A glow discharge is generated from the discharge bottle 2 due to the voltage applied to the laser gas, and energy is injected into the laser gas to excite and oscillate the laser beam, which is transmitted to the bending mirror 12 and the total reflection mirror 13.
The optical path is changed and the light is amplified and outputted from the partial reflecting mirror 14. When the laser gas passes through the glow discharge region, the remaining glow discharge energy that is not extracted as laser output is converted into heat and increases the temperature of the laser gas. The heated laser gas is absorbed by the heat receiving section of the heat pipe 11 of the heat exchanger 9 and carried by the wick inside the tube. The heat is radiated by the heat radiating fins 12 of the heat radiating section, and the cooled wick returns to the heat receiving section and is circulated. Perform efficient heat exchange. Since the heat dissipation part of the heat pipe protrudes to the outside, heat exchange efficiency can be significantly improved by increasing the size of the heat dissipation fins or adding cooling means.

Effects Since the present invention is constructed as detailed below, the present invention has the following effects.

In the CO2 gas laser oscillator of claim 1, since the heat dissipation part of the heat pipe protrudes outside the oscillator, the heat dissipation area is increased and the cooling means can be freely added, making the area of the heat receiving fins of the heat receiving part particularly large. It is possible to improve the heat exchange efficiency even if it is the same level as before. In addition, by making the heat receiving fins smaller and reducing the number of heat pipes, the resistance during laser gas circulation can be reduced, and as a result, the circulation flow rate can be increased, and the heat exchange efficiency can be increased to the same level or more than before. , it also contributes to the miniaturization of the oscillator.

In the CO2 gas laser oscillator according to the second aspect, although it is necessary to devise a heat dissipation part, the heat exchange efficiency can be increased more than before.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram of a laser oscillator, and FIG. 2 is a diagram showing a heat exchanger. ■...Cylinder 3...Electrode 4...Blower a 9...Heat exchanger 10...Heat receiving fin 11...Heat pipe I2/Radiating fin Patent applicant Okuma Iron Works Co., Ltd. AMADA Co., Ltd.

Claims (2)

[Claims] (1) A CO_2 gas laser oscillator in which a heat exchanger is provided in the laser gas path that is forcedly circulated between electrodes, characterized in that a heat pipe is used as the heat exchanger, and the heat dissipation part of the heat pipe is taken out outside the oscillator. CO_2 gas laser oscillator. (2) CO_2 according to claim 1, wherein the heat dissipation part of the heat pipe is located at a location other than the laser gas flow path inside the oscillator.
Gas laser oscillator.