JPH05110183A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To obtain a gas laser oscillator which reduces consumption of laser medium gas and lowers a running cost. CONSTITUTION:Signal values are applied to a control apparatus 15 with a high voltage power supply 3a which outputs signals of electrical power or current values to be supplied to discharge electrodes 2a, 2b and these are integrated to open an electromagnetically controlled valve 12a in the exhaust side to exhaust a laser medium gas from a cabinet 1 in accordance with the electrical power or current value supplied from the discharge electrodes 2a, 2b. Then, new laser medium gas is supplied to the cabinet 1 from a bomb 9 as much as the exhausted gas using a pressure sensor 13, a comparator 14 and an electromagnetically controlled valve 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillator capable of effectively controlling the exchange amount of laser medium gas.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing an example of a conventional gas exchange device of a triaxial orthogonal type carbon dioxide gas laser oscillator disclosed in Japanese Patent Laid-Open No. 63-78584, and FIG.
FIG. Reference numeral 1 is a housing in which a laser medium gas is enclosed. The laser medium gas in the housing 1 is generally a mixed gas of CO ₂ , N ₂ , and He, and is enclosed in the housing 1 in a negative pressure state of several tens Torr to several hundreds Torr. 2a and 2b are a pair of discharge electrodes, 3 is a discharge electrode 2
A high voltage power source for applying a high voltage between a and 2b, 4 is a blower for circulating the laser medium gas, and 5 is a heat exchanger for cooling the laser medium gas circulated by the blower 4. Reference numerals 6 and 7 are total reflection mirrors and partial reflection mirrors located in both longitudinal directions of the space provided between the discharge electrodes 2a and 2b, and these constitute an optical resonator. 8 is a laser beam.

Reference numeral 9 denotes a cylinder for supplying a new laser medium gas into the housing 1. In the case of a carbon dioxide laser, CO ₂ , N ₂ and He are the same as the components of the laser medium gas in the housing 1.
Is filled with a mixed gas consisting of. Reference numeral 10 denotes an electromagnetic valve provided between the cylinder 9 and the housing 1, which adjusts the supply amount of a new laser medium gas supplied from the cylinder 9 into the housing 1. Reference numeral 11 is a vacuum pump for exhausting the old laser medium gas in the housing 1, and 12 is an adjusting valve for adjusting the exhaust amount. Reference numeral 13 is a pressure sensor for measuring the gas pressure in the housing 1, and 14 is a comparator for opening and closing the solenoid valve 10 so that the pressure of the medium gas in the housing 1 becomes a set value with respect to the set gas pressure. is there.

Next, the operation of the conventional gas exchange device of the carbon dioxide gas laser oscillator configured as described above will be described. When a high voltage is applied from the high voltage power supply 3 to the discharge electrodes 2a and 2b, a discharge is generated in the space between the discharge electrodes 2a and 2b. This discharge causes the laser medium gas in the space between the discharge electrodes 2a and 2b to be in an excited state. The excited laser medium gas moves to a stable energy level, and only the 10.6 μm light generated at this time travels back and forth between the total reflection mirror 6 and the partial reflection mirror 7, and a part thereof is amplified. The laser beam 8 is taken out to the outside. The energy of the laser beam 8 is about 10% to 20% of the energy input to the discharge electrodes 2a and 2b, and the remaining 80% to 90%.
% Increases the temperature of the laser medium gas as thermal energy. Therefore, the laser medium gas after discharge is sent to the heat exchanger 5 by the blower 4 to be cooled, and the discharge electrode 2 is again discharged.
It is circulated in the space between a and 2b.

However, this laser medium gas is dissociated as CO ₂ → CO + O ₂ by the discharge energy, and the concentration of CO ₂ in the circulated laser medium gas decreases, so that the laser beam extracted with respect to the discharge energy Since the ratio of 8 decreases, the old laser medium gas must be replaced with a new laser medium gas in sequence. Therefore, the laser medium gas in the housing 1 is exhausted by the adjusting valve 12 and the vacuum pump 11. As a result, the pressure sensor 13 measuring the gas pressure in the housing 1
Output voltage decreases, the comparator 14 opens the electromagnetic valve 10 so that the pressure of the medium gas in the housing 1 becomes a set value with respect to the set gas pressure, and the medium gas is stored in the housing 1. The medium gas pressure in the housing 1 is supplied to the set gas pressure value. In this way, a new laser medium gas is constantly supplied to the housing 1 in a predetermined amount, is exchanged with the old laser medium gas, and a stable laser beam is continuously extracted.

[0006]

A gas exchange device for a conventional carbon dioxide gas laser oscillator configured as described above (Japanese Patent Application Laid-Open No. 6-58242).
In Japanese Patent Laid-Open No. 3-78584), since the laser medium gas is exchanged regardless of the operating state of the carbon dioxide laser oscillator, there is a problem that the consumption amount of the laser medium gas is very large and the running cost is high. In addition to the conventional example described above, Japanese Patent Application Laid-Open No. 60-52081 also discloses a conventional gas exchange device for a carbon dioxide gas laser oscillator. This device continuously sucks mixed gas in a vacuum container. However, they are not properly replaced according to the operating conditions, and therefore the above problems cannot be solved sufficiently.

The present invention has been made to solve the above-mentioned problems, and the laser medium gas can be appropriately exchanged according to the operating state of the gas laser oscillator, so that the consumption amount of the laser medium gas is reduced and the running cost is low. An object of the present invention is to obtain a gas laser oscillator including the gas exchange device.

[0008]

A gas laser oscillator according to the present invention detects a power amount or a current value supplied from a high voltage power source to a discharge electrode, and a gas exchange device for a laser medium gas is provided according to the detected amount. It is designed to be controlled.

[0009]

Function: The discharge power amount or current value of the gas laser oscillator is detected to know the operating state of the gas laser oscillator, and the laser medium gas is appropriately exchanged accordingly.

[0010]

Embodiment 1 FIG. 1 is a block diagram showing an embodiment of the present invention. Note that FIG.
The same or corresponding portions as those of the conventional example shown by are denoted by the same reference numerals, and the description thereof will be omitted. The figure shows a triaxial orthogonal carbon dioxide laser oscillator in which the discharge direction, the gas flow direction, and the laser beam direction are orthogonal to each other. 3a applies a high voltage to the discharge electrodes 2a and 2b, and supplies it to the discharge electrodes 2a and 2b. It is a high voltage power supply having a function of detecting the state of the amount of electric power or the current value to be applied. Reference numeral 15 is a control device that receives the state of the supplied electric power detected by the high-voltage power supply 3a as an electric signal and performs time integration of the signal value, and 12a is the control device 1.
It is an electromagnetic valve that opens and closes according to a command from 5.

Next, the operation of the first embodiment constructed as above will be described. Note that the oscillation operation of the carbon dioxide gas laser oscillator and the reduction of the CO ₂ concentration in the laser medium gas are the same as those described in the conventional example, and therefore description thereof is omitted. The high-voltage power supply 3a applies a voltage to the discharge electrodes 2a and 2b, and at the same time detects the amount of electric power or the current value supplied to the discharge electrodes 2a and 2b. The electric signal indicating the state is transmitted to the control device 15, and the electric signal value is temporally integrated. A control signal is sent from the control device 15 to the electromagnetic valve 12a, the electromagnetic valve 12a is opened by an amount corresponding to the electric energy or the current value supplied to the discharge electrodes 2a and 2b, and the laser medium gas is exhausted by the vacuum pump 11. It As a result, the pressure sensor 13 measuring the gas pressure in the housing 1
Of the medium gas in the housing 1, the comparator 14 opens the solenoid valve 10 so that the pressure of the medium gas in the housing 1 becomes a set value with respect to the set gas pressure. Bring the pressure to the set gas pressure value. In this way, a new laser medium gas is always supplied to the housing 1 in a predetermined amount, and the old laser medium gas is replaced with a stable laser beam.

In the above-mentioned first embodiment, the electric signal value is integrated over time, but the discharge power amount or current value when the rated value is laser-outputted by continuous laser oscillation is set to 100%. In this case, for example, when used with ON / OFF oscillation of 50%, the temporal integrated value of the electric signal value is 50.
%, ON-OFF transmitted to the electromagnetic valve 12a
Since the signal is 50% ON and 50% OFF, the laser medium gas exhausted by the vacuum pump 11 becomes half as compared with the case of continuous use. That is, the pressure sensor 13 and the comparator 1 are arranged so that the gas pressure in the housing 1 is constant.
The ON-OFF ratio of the solenoid valve 10 controlled by 4 also becomes 1/2, and the new laser medium gas supplied from the laser medium gas cylinder 9 also becomes 1/2.

By the way, the gas laser oscillator is mainly used as a laser source of a laser beam machine. In this case, the laser beam machine condenses the laser beam and irradiates the work piece, and cuts or welds the work piece. The time during which the workpiece is irradiated with the laser beam is generally about 50%, and it is 8 times the rated output value of the gas laser oscillator.
Only about 0% is used. From this, by using the control means of the first embodiment, the medium gas consumption of the gas laser oscillator becomes 50% × 80% = 40%.
0% of laser medium gas can be saved.

Embodiment 2 FIG. 2 is a block diagram showing a second embodiment of the present invention. 10
Reference numeral a is an electromagnetic valve that opens and closes in response to a command from the control device 15, and reference numeral 12b is an electromagnetic valve provided on the exhaust side that opens and closes in response to a signal from the comparator 14.

Next, the operation of the second embodiment constructed as described above will be described. The high-voltage power supply 3a includes discharge electrodes 2a and 2b.
A voltage is applied to the discharge electrodes 2a and 2b, but at the same time, the amount of electric power or current value supplied to the discharge electrodes 2a and 2b is detected. The electric signal indicating the state is transmitted to the control device 15, and the electric signal value is temporally integrated. A signal is sent from the control device 15 to the electromagnetic valve 10a, the electromagnetic valve 10a is opened, and new laser medium gas is supplied into the housing 1. On the other hand, the pressure sensor 13 that measures the gas pressure in the housing 1
Detects a rise in the gas pressure in the housing 1 and sends a signal to the comparator 14 so that the pressure of the medium gas in the housing 1 becomes a set value with respect to the set gas pressure. Solenoid valve 1
2b is opened, the laser medium gas is exhausted by the vacuum pump 11, and the medium gas pressure in the housing 1 is set to the set gas pressure value. In this way, a new laser medium gas is always supplied to the housing 1 in a predetermined amount, and the old laser medium gas is replaced with a stable laser beam.

In the first and second embodiments, the carbon dioxide gas laser oscillator of the triaxial orthogonal type in which the discharge direction, the gas flow direction, and the laser beam direction are orthogonal to each other has been described. However, the laser oscillator may be a laser oscillator of another type.

[0017]

As is apparent from the above description, according to the present invention, the laser medium gas exchange device of the gas laser oscillator is controlled by the amount of electric power or the current value supplied from the high voltage power supply to the discharge electrode. The amount of the laser medium gas consumed by the gas laser oscillator is commensurate with the operating state of the gas laser oscillator, and the laser medium gas can be saved. Further, the laser medium gas can be easily saved by controlling the exhaust side electromagnetic valve or the supply side electromagnetic valve according to the detected signal, rather than controlling the entire laser medium gas exchange device.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing an example of a conventional gas laser oscillator.

4 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 11 Case 2a, 2b Discharge electrode 3a High voltage power supply 4 Blower 5 Heat exchanger 6 Total reflection mirror 7 Partial reflection mirror 8 Laser beam 9 Cylinder 10, 10a, 12a, 12b Electromagnetic valve 11 Vacuum pump 13 Pressure sensor 14 Comparator 15 Control device

Claims (1)

[Claims] 1. A high-voltage power supply for supplying energy between a pair of discharge electrodes to cause a discharge, an optical resonator for extracting laser energy from a laser medium gas excited by the discharge, and the laser medium gas are replaced. In a gas laser oscillator including a gas exchange device, etc., means for detecting the amount of electric power or current value supplied from the high-voltage power supply to the discharge electrode, and controlling the gas exchange device for the laser medium gas according to the detected amount And a gas laser oscillator.