JPS62186579A - Gas controlling method for laser oscillator - Google Patents

Abstract

PURPOSE:To reduce the consumption of a laser gas, by performing the exhaust and supply of a laser gas at every specified time or based on the detection result of a deteriorated gas. CONSTITUTION:During a laser oscillation, a deteriorated gas is exhausted at a previously set time by an exhausting system 25, and, at the same time, a new laser gas is supplied from a mixed gas tank 27. Exhausting and supplying operations like this are performed with a specified period. Instead of this method, a gas exchange is available wherein the exhausting system 25 and a gas mixing system 29 are operated only in the case of occurrence of gas deterioration whose degree is detected by a sensor 35. Thereby, the consumption of gas can be reduced as compared with a method wherein exhausting and supplying gas are always performed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gas control method for a laser oscillator, and more specifically, the present invention relates to a gas control method for a laser oscillator. The present invention relates to a gas control method for supplying and exhausting new laser gas and exhausted laser gas, respectively, for a certain amount of time.

[Conventional technology]

Conventionally, in laser oscillators such as carbon dioxide (GO2) laser oscillators, there have been two methods: a containment method in which a mixed gas is sealed in a laser tube as the laser medium, and a new mixed gas while constantly exhausting part of the gas degraded by discharge into the atmosphere. A gas flow one-way type is known, in which the gas flow is input and used, and the latter gas 70 one-way type is generally adopted.

(Problem to be solved by the invention) However, in the generally adopted gas flow one-type system, in order to keep the pressure inside the laser tube constant, a part of the deteriorated gas is constantly exhausted to the atmosphere while a new mixed gas is pumped in. We are investing. Therefore, a large amount of laser gas is required for long-time oscillation, which has the disadvantage of worsening running costs.

The purpose of the present invention was proposed in order to solve the problem in view of the above circumstances, and the purpose of the present invention is to limit the supply time of laser gas during laser oscillation, and reduce the convexity of the laser gas to be supplied and the amount of degraded gas exhausted. The present invention provides a gas control method for a laser oscillator that reduces the amount of laser gas consumed.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for supplying a constant amount of laser gas to a laser oscillation section connected to a laser gas circulation device in a laser oscillator, and supplying a constant amount of laser gas between an anode and a cathode appropriately arranged in the laser gas oscillation section. While the discharge is being performed and the laser beam is being output from the laser oscillation section, new laser gas is supplied at preset time intervals, and new laser gas is supplied for the exhaust time, and the previously supplied laser gas is exhausted. It is characterized by this.

A second invention is such that while the laser oscillator is outputting a laser beam, deterioration of the laser gas is detected by a detection device, and at the time of detection, new laser gas and exhausted laser gas are respectively supplied and exhausted for an appropriate time. It is characterized by this.

[Effect]

By employing the gas control method of the present invention, when using laser gas at the same mixing ratio as in the past, it is possible to reduce the amount of laser gas consumed during the time when new laser gas supply is stopped.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

Referring to FIG. 1, a laser oscillator 1 includes a laser tube 3 for resonant amplification of excitation light, and a laser gas containing helium (He), nitrogen (N2), and carbon dioxide gas (CO2) mixed in an appropriate ratio. It consists of a laser gas circulation device 5 that supplies and circulates the laser gas into the laser tube 3. An anode 7 and a cathode 9 are appropriately arranged in the laser tube 3 to generate a discharge.
A total reflection mirror 11 and an output mirror 13 are attached to the end portion. In order to generate a discharge between the anode 7 and the cathode 9, the anode 7 and the cathode 9 are connected to a high voltage power supply circuit 15.
It is connected to. The laser gas circulation device 5 includes a heat exchanger 17 that cools the laser gas from the laser tube 3 and a blower 19 that supplies the laser gas to the laser tube 3. Supply route 23
Connect via .

With the above configuration, the blower 19 is driven to circulate the laser gas, and the high voltage power supply circuit 15 drives the anode 7 and the cathode 9.
A high voltage is applied between the anode 7 and the cathode 9 to generate a discharge between the anode 7 and the cathode 9, so that the laser beam LB is output from the output mirror 13 side.

An exhaust system 25 is connected to an appropriate position of the gas return path 21 in order to exhaust a portion of the laser gas deteriorated by the discharge between the anode 7 and the cathode 9. On the other hand, a gas mixing tank for supplying new laser gas is connected to an appropriate position of the gas supply path 23. This mixing tank 27 contains He, N2,
A gas mixing system 29 for mixing various gases including CO2 at appropriate ratios is connected. This gas mixing system 2
9 includes a plurality of gas cylinders 31A containing various gases;
31B and 31G are connected appropriately. For example, 1-1e for gas cylinder 31A and N2 for gas cylinder 31B.
The gas cylinder 31C contains CO2. Therefore, a portion of the laser gas degraded by the discharge in the laser tube 3 is exhausted from the exhaust system 25, and new laser gas is introduced from the gas mixing tank 27 via the gas mixing system 29.

A control device 33 is provided to appropriately control said exhaust system 25 and gas mixing system 29.

The control device 33 is composed of a computer or a numerical control device, and various controls are programmed in advance. Therefore, the exhaust system 25 is controlled by the control device 3.
Under the control of the controller 3, a part of the laser gas is continuously or intermittently exhausted, and furthermore, the gas mixing system 29 continuously or intermittently mixes various gases at appropriate ratios under the control of the controller 33. It will be done accordingly.

The laser oscillator 1 shown in FIG.
He, N2, and CO2 contained in 1A, 31B, and 31C are supplied to the gas mixing system 29 and mixed at an appropriate ratio, and the mixed laser gas is temporarily stored in the mixed gas tank 27. A certain amount of the mixed laser gas stored in the mixed gas tank 27 is sealed in the laser tube 3 via the gas supply path 23 and is not exhausted from the exhaust system 25 via the gas return path 21. In this state, the laser tube 3
A high voltage power supply device 15 is connected between the anode 7 and the cathode 9 arranged in the
When a high voltage is applied, the laser beam is emitted from the output mirror 13 side. As shown in FIG. 2, the output curve A of the laser beam based on the change over time has already been determined through actual measurements. That is, in FIG. 2, it has been found that after a certain 71 hours, for example about 8 hours, have passed since the output beam was output, the gas gradually deteriorates and the output power of the laser beam decreases. Utilizing this knowledge, in this embodiment, as shown in FIG.
A predetermined amount of mixed laser gas is sealed in the laser tube 3 via 3. From the state in which the mixed laser gas is sealed in this way, a preset time T2 shorter than the above-mentioned T1 time is reached.
When the laser gas reaches the exhaust system 2, the deteriorated laser gas is
5 to 13 hours, and new laser gas is pumped from the mixed gas tank 27 for Tα time until 13 hours.
Supply only α time. (3) After exhausting and supplying the laser gas for α time, the exhaust and supply are stopped after 13 hours, and the laser gas is confined in the laser tube 3 for a preset time of 10 hours, which is roughly shorter than T1 time. At 14 hours after 10 hours have passed, the laser gas that has deteriorated to 15 hours, which is the time Tα mentioned above, is exhausted from the exhaust system 25, and the mixed gas tank 2
7, new laser gas is supplied to keep the laser output inside the laser tube 3 constant.

After that, by repeating the same operation, the laser tube 3
The laser power within can be kept constant.

In the example described above, the time corresponding to the amount of deterioration of the laser gas is set in advance. It is connected. The sensor 35 of the detection device constantly detects the decreased laser beam in the laser tube 3, and the control device 33 operates the exhaust system 25 and gas mixing system 29 to exhaust a certain amount of the deteriorated laser gas, and This is to supply new laser gas. In addition, instead of the sensor 35 of the detection device placed on the side of the total reflection mirror 11, a sensor 37 for detecting the degree of separation of the mixed laser gas is placed in a part of the laser gas circulation device 5 in the laser gas circulation path, and the sensor 37 is connected to the control device @ It is also possible to use a means connected to 37 to detect deterioration of the laser gas.

Therefore, the amount of laser gas consumed can be reduced by exhausting and supplying the laser gas at each setting without constantly exhausting and supplying the laser gas.

〔effect〕

As can be understood from the description of the embodiments described above, according to the present invention, the laser gas is not constantly exhausted and supplied to the laser tube, but the laser gas is pumped at a preset time or based on the detection of deteriorated laser gas. Since the exhaust and supply are performed for each setting, the amount of laser gas consumed can be reduced by the amount of time during which the supply and exhaust of the laser gas are stopped. Moreover, since the exhaust and supply of laser gas is restarted before the output of the laser beam decreases, there is no decrease in output. The present invention is particularly effective when operating a laser oscillator for a long time.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram schematically showing the overall configuration of a gas laser oscillator. FIG. 2 is a graph showing changes over time in a gas flow type laser beam in a laser oscillator. FIG. 3 is a graph showing an example of the method of the present invention. (Numbers and explanations representing main parts of the drawing) 1... Laser oscillator 3... Laser tube 5... Laser gas circulation device 7... Anode 9... Cathode 25... Exhaust system 29... Gas mixing system 35.37...sensor

Claims (4)

[Claims] (1) A fixed amount of laser gas is supplied to a laser oscillation unit connected to a laser gas circulation device in a laser oscillator, a discharge is caused between an anode and a cathode appropriately arranged in the laser gas oscillation unit, and a laser beam is emitted from the laser oscillation unit. A gas control method for a laser oscillator, characterized by supplying new laser gas for an appropriate supply and exhaust time at every preset time while outputting the laser gas, and exhausting the laser gas that has been supplied in advance. (2) A fixed amount of laser gas is supplied to the laser oscillation unit connected to the laser gas circulation device in the laser oscillator, a discharge is caused between an anode and a cathode appropriately placed in the laser gas oscillation unit, and a laser beam is emitted from the laser oscillation unit. A gas control method for a laser oscillator, characterized by detecting deterioration of the laser gas with a detection device while outputting the laser gas, and at the time of detection, supplying and exhausting new laser gas and exhausted laser gas, respectively, for an appropriate time. (3) The gas control method for a laser oscillator according to claim 2, wherein the detection device detects deterioration of the laser gas by detecting a decrease in laser output. (4) A gas control method for a laser oscillator according to claim 2, wherein the detection device is provided in a part of the laser gas circulation path to directly detect deterioration of the laser gas.