JP3986746B2 - Gas laser oscillator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas laser oscillation device.
[0002]
[Prior art]
A conventional gas laser oscillation device will be described below. FIG. 3 shows a conventional gas laser oscillation apparatus. In FIG. 3, la and 1b are blowers, 2a, 2b, 2c and 2d are discharge tubes, 3a, 3b, 3c, 3d, 4a, 4b, 4c and 4d are installed in the vicinity of the discharge tubes 2a, 2b, 2c and 2d. Electrode. Reference numerals 5a, 5b, 5c and 5d denote high-voltage power supplies connected to the electrodes 3a, 3b, 3c, 3d, 4a, 4b, 4c and 4d, respectively, and 6 denotes a discharge space. Reference numeral 7 denotes a total reflection mirror, and 8 denotes a partial transmission mirror, which constitutes an optical resonator. 9a, 9b, 9c and 9d are heat exchangers, 10 is a laser beam taken out from the partial transmission mirror 8, 11a, 11b, 11c, 11d and 11e are laser gas pipes, 12a, 12b, 12c and 12d are laser gas, and 13 is a vacuum. A pump, 14 is a laser gas cylinder, 15 is a discharge flow rate regulator, 16 is a supply flow rate regulator, 17 is a control unit, 18 is a signal line, and 19 is a pressure detector.
[0003]
The operation of the gas laser oscillation apparatus configured as described above will be described. The laser gas pipes 11a, 11b, 11c, and 11d are passed through the blowers 1a and 1b, and the laser gases 12a, 12b, 12c, and 12d are forcibly circulated through the discharge tubes 2a, 2b, 2c, and 2d. At this time, the laser gases 12a and 12b discharged from the blower 1a pass through the laser gas pipes 11a and 11b and flow to the discharge tubes 2a and 2b, and the laser gases 12c and 12d discharged from the blower 1b pass through the laser gas pipes 11c and 11d. It flows through the discharge tubes 2c and 2d, respectively. The piping paths of the blowers 1a and 1b are connected by a piping 11e provided on the electrodes 4b and 3c side of the discharge tubes 2b and 2c, and the pressures in the discharge tubes 2a, 2b, 2c and 2d are made equal.
[0004]
The electrodes 3a, 3b, 3c, 3d, 4a, 4b, 4c, 4d are installed in the laser gas circulation system in the vicinity of the discharge tubes 2a, 2b, 2c, 2d. At this time, the high voltage power supplies 5a, 5b, 5c, A high voltage is applied to the discharge space 6 from the electrodes 3a, 3b, 3c, 3d, 4a, 4b, 4c, and 4d connected to 5d, and glow discharge is generated inside the discharge tubes 2a, 2b, 2c, and 2d.
[0005]
Since the laser gases 12a, 12b, 12c, and 12d are compressed and discharged from the blowers 1a and 1b and have a high temperature, they are cooled by the heat exchangers 9b and 9d disposed on the downstream side of the blowers 1a and 1b. The laser gases 12a, 12b, 12c, and 12d that have passed through the discharge space 6 are also cooled by the heat exchangers 9a and 9c because discharge energy is applied and the temperature becomes high.
[0006]
The laser gases 12a, 12b, 12c, and 12d excited by the glow discharge oscillate and are amplified while the laser beam reciprocates between the total reflection mirror 7 and the partial transmission mirror 8 to be in a resonance state. From this resonance state, a part of the laser beam between the total reflection mirror 7 and the partial transmission mirror 8 is extracted from the partial transmission mirror 8 as a laser beam 10 to the outside of the resonator. This laser beam 10 is used for processing such as metal cutting and welding.
[0007]
A part of the laser gas 12a, 12b, 12c, 12d is taken out by the vacuum pump 13 through the discharge flow rate regulator 15 and discarded. A new laser gas having the same amount as the discarded laser gas is supplied from the cylinder 14 through the supply flow rate regulator 16 into the gas laser oscillation device so that the internal pressure is kept constant. The internal pressure is detected by the pressure detector 19 and a signal is sent to the control unit 17. Both or one of the supply flow rate adjuster 15 and the discharge flow rate adjuster 16 is controlled so as to have a preset pressure in the control unit 17.
[0008]
In such a gas laser oscillation apparatus, a laser beam is generated between the total reflection mirror 7 and the partial transmission mirror 8, so that no part can be disposed on this axis, and the gap between the total reflection mirror 7 and the partial transmission mirror 8 can be determined. It was necessary to secure as space. For this reason, the discharge tubes 2b and 2c arranged on the shaft are inevitably spatially connected, and as a result, the laser gas piping 11e is connected.
[0009]
[Problems to be solved by the invention]
However, the above configuration has a problem that the flow rates of the laser gases 12a, 12b, 12c, and 12d flowing through the discharge tubes 2a, 2b, 2c, and 2d are different.
[0010]
The flow rate of the laser gas flowing in the discharge tubes 2a, 2b, 2c and 2d is determined by the differential pressure between the suction side and the discharge side of the blowers 1a and 1b. In the conventional gas laser oscillator, the suction sides of the blowers 1a and 1b are connected to the pressure detector 19 after being connected to each other by a T-shaped pipe. For this reason, since the suction sides of the fans 1a and 1b are directly connected, the laser gas pressures are almost equal. However, in the vicinity of the discharge side of the blowers 1a and 1b, the pipe is not connected, and therefore the laser gas pressure in the discharge portion of the blowers 1a and 1b differs depending on factors such as variations due to individual differences. Although the discharge tubes 2b and 2c are connected by a laser gas pipe 11e, the discharge parts of the blowers 1a and 1b are disposed at positions away from the discharge parts of the blowers 1a and 1b with the laser gas pipes 11b and 11c interposed therebetween. No effect was obtained until the laser gas pressures were made equal.
[0011]
Thus, even if the pressure on the suction side is the same, the pressure on the discharge side is different, so that there is a difference in the differential pressure between the fans 1a and 1b. Due to the difference in the differential pressure, the flow rates of the laser gas discharged from the blowers 1a and 1b are not equal, and there is a difference in the flow rates of the laser gases 12a, 12b and 12c and 12d flowing in the discharge tubes 2a, 2b and 2c and 2d, respectively. It was. If there is a difference in the flow rate of the laser gas flowing in each discharge tube, a phenomenon that the laser output becomes unstable occurs. In a normal gas laser oscillator, the high voltage and current applied to each discharge tube are controlled to be equal. This is to prevent a problem that discharge occurs at a place other than the discharge space 6 that should be discharged if there is a large difference in the applied high voltage. Although almost the same high voltage and current are applied to each discharge tube, if the laser gas flow rate is low, the heat capacity is small, causing the laser gas temperature to rise, and the negative temperature distribution state necessary for laser oscillation collapses. It was easy to cause a decrease in output. In particular, when the gas laser oscillation device is used for a long period of time, consumables deteriorate over time such as wear of the electrodes 3a, 3b, 3c, 3d, 4a, 4b, 4c, and 4d, and a decrease in reflectivity of the total reflection mirror 7 and the partial transmission mirror 8. Come on. In order to compensate for the decrease in the laser output due to the deterioration of the consumables, when the current applied to the discharge tube is increased, the discharge tube with a low laser gas flow rate has a lower laser output for the above reason.
[0012]
When the laser output is reduced due to such a cause, the metal cutting has an adverse effect on the processing, for example, the good cutting becomes impossible. Maintaining the laser output stably is an important factor in performing processing such as metal cutting and welding, and the reduction in the output has caused the quality of the processed product to deteriorate and cause defects.
[0013]
Although there is a request from a user who uses the gas laser oscillation device to maintain a stable processing quality for a longer period of time, it has been difficult to realize the conventional gas laser oscillation device for the above-described reason.
[0014]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a gas laser oscillation device capable of maintaining stable processing quality for a long period of time.
[0015]
[Means for Solving the Problems]
Gas laser oscillator apparatus of claim 1 wherein the flow of laser gas therein, and a discharge tube for discharge excitation laser gas by electrodes connected to a power source, a pipe path for circulating the laser gas is connected to the discharge tube, the pipe comprising at least one pair of circulating path which kicked set a path comprising a blower for circulating the laser gas having a suction side pipe communicating between the suction side of said pair of blower, separate the pair from the pair of circulating path The discharge side piping which connects between the discharge side of this air blower is provided .
[0016]
According to the gas laser oscillation device of claim 1, since there is no difference in the differential pressure between the suction side and the discharge side of the blower in the pair of circulation paths, and the laser gas flow rate becomes equal, the laser output can be stabilized, and the difference between the blowers It is possible to suppress a decrease in laser output with respect to use time when the pressures are not equal, and an excellent effect is achieved that can realize a gas laser oscillation device capable of maintaining high-quality processing performance for a long period of time.
[0017]
According to a second aspect of the present invention, there is provided the gas laser oscillation device according to the first aspect, wherein the suction side pipe communicates between the pair of discharge tubes.
[0018]
According to the gas laser oscillator of the second aspect, the same effect as that of the first aspect is obtained.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The operation of the embodiment of the present invention will be described below with reference to FIG. The description of the same configuration as the conventional example shown in FIG. 3 is omitted.
[0020]
In FIG. 1, as a difference from FIG. 3, the present invention has a configuration in which discharge portions of the fans 1 a and 1 b are connected by a laser gas pipe 11 f. Since the discharge parts are directly connected, it is possible to make the laser gas pressures of both the same. Since the pressure in the suction portion is originally the same, the differential pressure between the suction and discharge of the two blowers 1a and 1b becomes equal, so the laser gas flow rates discharged by the blowers 1a and 1b are equal. Since the laser gas flows of the discharge tubes 2a to 2d are the same, the applied high voltage and current can be raised to a threshold level that does not disturb the negative temperature distribution of all the discharge tubes, and an efficient and stable laser output is taken out. be able to.
[0021]
FIG. 2 shows the change of the laser output with respect to the usage time of the gas laser oscillator. As an example, a gas laser oscillator with an output of 2 kW is taken up. Curve A is a conventional example, and curve B is an embodiment of the present invention. As can be seen from FIG. 2, in the curve A of the conventional example, the laser output starts to decrease after 1000 hours have passed, but in the example curve A of the present invention, the decrease in the laser output is hardly observed even after 3000 hours. I can't. In the conventional example, since the laser output is rapidly reduced, the processing quality is deteriorated in a short period of time. On the other hand, in the example of the present invention, the reduction rate of the laser output with respect to the use time is reduced as compared with the conventional example, so that it is possible to maintain high quality processing performance over a long period of time.
[0022]
In the present invention, two or more blowers may be provided for each piping path , and two or more circulation paths including discharge tubes and piping paths may be provided.
[0023]
【The invention's effect】
According to the gas laser oscillation device of claim 1, since there is no difference in the differential pressure between the suction side and the discharge side of the blower in the pair of circulation paths, and the laser gas flow rate becomes equal, the laser output can be stabilized, and the difference between the blowers It is possible to suppress a decrease in laser output with respect to use time when the pressures are not equal, and an excellent effect is achieved that can realize a gas laser oscillation device capable of maintaining high-quality processing performance for a long period of time.
[0024]
According to the gas laser oscillator of the second aspect, the same effect as that of the first aspect is obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas laser oscillation apparatus according to an embodiment of the present invention.
FIG. 2 is a correlation diagram between a use time of a gas laser oscillation device and laser output.
FIG. 3 is a configuration diagram of a conventional gas laser oscillation apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1a Blower 1b Blower 2a Discharge tube 2b Discharge tube 2c Discharge tube 2d Discharge tube 3a Electrode 3b Electrode 3c Electrode 3d Electrode 4a Electrode 4b Electrode 4c Electrode 4d Electrode 5a High voltage power source 5b High voltage power source 5c High voltage power source 5d High voltage power source 6 Discharge Space 7 Total reflection mirror 8 Partial reflection mirror 9a Heat exchanger 9b Heat exchanger 9c Heat exchanger 9d Heat exchanger 10 Laser beam 11a Laser gas piping 11b Laser gas piping 11c Laser gas piping 11d Laser gas piping 11e Laser gas piping 12a Laser gas 12b Laser gas 12c Laser gas 12d Laser gas 13 Vacuum pump 14 Laser gas cylinder 15 Supply flow rate regulator 16 Discharge flow rate regulator 17 Control unit 18 Signal line 19 Output detector

Claims (2)

Flowing laser gas therein, circulation and discharge pipe for discharge excitation laser gas by electrodes connected to a power source, a pipe path for circulating the laser gas connected to the discharge tube, a set vignetting in the laser gas in the pipe path comprising at least one pair of circulating path consisting of the make blower has a suction side pipe communicating between the suction side of said pair of blower, communicating between separate discharge side of the pair of blowers and the pair of circulating path discharge Gas laser oscillation device with side piping. The gas laser oscillation apparatus according to claim 1, wherein the suction side pipe communicates between the pair of discharge tubes.

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