JP2660875B2 - Gas laser device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser device such as a carbon dioxide gas laser, and more particularly to a gas laser device in which the size of a high-voltage power supply is reduced and the output voltage is stabilized.

2. Description of the Related Art A configuration example of a conventional gas laser device will be described with reference to FIG. In FIG. 4, 1 is a laser resonator, 2 is an output mirror, 3 is a total reflection mirror, 4a and 4b are discharge electrodes, 5 is a discharge part of a gas laser medium in the laser resonator 1, 6 is a blower, 7 is A cooler, 8 is an air supply duct, and 9 is an exhaust duct. 10 is a commercial power supply, 11 is a high voltage transformer, 12 is a high voltage rectifier diode, 13 is a smoothing capacitor, 14 is a high voltage resistor, and 15 is a control vacuum tube.

FIG. 3 shows a configuration example of the high-voltage transformer 11,
16 is an iron core, 17 is a transformer coil wound vertically on the iron core 16, 18 is a transformer support supporting the iron core 16, 19 is a transformer container accommodating the iron core 16, the transformer coil 17 and the transformer support 18, 20 Is an insulating oil filled in the transformer container 19, 19 a is a transformer container top plate for sealing the transformer container 19, and 19 b and 19 c are fin-shaped cooling provided on an outer wall of the transformer container 19 for cooling the insulating oil 20. Reference numeral 17a denotes a primary input terminal mounted on the top of the transformer container top plate 19a, and 17b denotes a high-voltage insulator mounted on the top of the transformer container top plate 19a.

Next, the operation of the conventional example will be described. In FIG. 4, the gas laser medium in the laser resonator 1 is a blower 6
Is supplied into the laser resonator 1 through the air supply duct 8 and is excited by the discharge of the discharge electrodes 4a and 4b connected to the high-voltage power supply to generate laser light. The generated laser light is amplified while reciprocating between the output mirror 2 and the total reflection mirror 3, and is extracted from the output mirror 2 to the outside. Laser resonator 1
The gas laser medium whose temperature has risen inside is recovered through the exhaust duct 9, cooled by the cooler 7, and supplied again into the laser resonator 1 through the air supply duct 8.

A high voltage for discharging and exciting the gas laser medium is obtained, for example, by boosting a 200 V commercial power supply 10 with a high-voltage transformer 11, rectifying it with a high-voltage rectifier diode 12, smoothing it with a smoothing capacitor 13, a high-voltage resistor 14 and a control vacuum tube 15. To control the current and voltage, and are applied to the discharge electrodes 4a and 4b of the laser resonator 1.

Generally, in this type of gas laser device, a high-voltage transformer is used.
11 to discharge start voltage 30 to 5 from commercial 100 to 200 V voltage
Since the voltage is boosted to 0 kV, it is necessary to use large high-voltage transformer 11, high-voltage rectifier diode 12, and smoothing capacitor 13 in order to take insulation dimensions, and there is a problem that the power supply becomes large. In addition, the conventional high-voltage transformer 11
The transformer coil 17 is wound in the vertical direction with the iron core 16 arranged vertically to increase the pressure at a low commercial frequency.
When the oil level fluctuates, the insulating oil 20 runs out at the top of the transformer coil 17, the voltage drops due to insulation breakdown due to insufficient withstand voltage, and the output of the high-voltage power supply becomes unstable with time. .

An object of the present invention is to solve such a conventional problem and to provide a gas laser device capable of miniaturizing a high-voltage power supply of a gas laser device and stabilizing an output voltage of the power supply. I do.

Means for Solving the Problems In order to achieve the above object, a gas laser device according to the present invention comprises a high-voltage power supply, an effective voltage that can be changed, and a frequency that is variable.
Including a low-voltage AC power supply of 1 kHz or more, a boost transformer and a rectifier circuit, the boost transformer and the rectifier circuit are mounted in a transformer container filled with insulating oil, and an insulating partition plate having a through hole is provided in the insulating oil, A boost transformer is arranged below the insulating partition plate, and a rectifier circuit is arranged above the insulating transformer.

According to the present invention, the above configuration allows the insulating oil in the transformer container to rise by being heated by the heat generated by the coil and the iron core of the step-up transformer, and to pass through the through hole of the insulating partition plate to the upper room where the rectifying circuit is arranged. And then cooled in that room and again into the lower room through the through holes in the insulating partition plate and convectively circulate in the transformer vessel. For this reason, the insulating oil does not always flow and stagnates in the coil portion.
Since the movement of the upper insulating oil is blocked by the insulating partition plate, no oil shortage occurs in the coil due to fluctuations in the oil level, and a decrease in the dielectric strength of the coil can be prevented. As a result, the output voltage can be prevented from becoming unstable to stabilize the laser light output, and the insulation distance can be shortened, so that both the iron core and the rectifier circuit can be mounted in the same transformer container. The size of the power supply can be reduced.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a step-up transformer in one embodiment of the present invention, and FIG. 2 shows the configuration of a gas laser device in one embodiment of the present invention. First, in FIG.
21 is a laser resonator, 22 is an output mirror, and 23 is a total reflection mirror.
24a and 24b are discharge electrodes, 25 is a discharge part of the gas laser medium in the laser resonator 21, 26 is a blower, 27 is a cooler, 28 is an air supply duct, and 29 is an exhaust duct. Reference numeral 30 denotes a low-voltage AC power supply, and reference numeral 31 denotes an inverter circuit serving as a low-voltage AC power supply having a frequency of 1 kHz or more, and includes four semiconductor switch elements connected in full bridge. Reference numeral 32 denotes a step-up transformer in which the primary coil and the secondary coil are coaxially wound and insulated.
An inverter circuit 31 is connected to the primary side. 33 is a rectifier diode connected in parallel to the secondary side of the step-up transformer 32, 34 is a smoothing capacitor connected in parallel to the rectifier diode 33, and both ends of the smoothing capacitor 34 are connected to the discharge electrodes 24a and 24b. Have been. The rectifier diode 33 and the smoothing capacitor 34 constitute a rectifier circuit.

As shown in FIG. 1, the step-up transformer 32 is arranged such that both legs 35a and 35b of a ferrite core 35 which is an iron core are horizontal, and both sides thereof are inserted into grooves provided in core holders 36 and 37. By attaching these core holders 36 and 37 to the lower surface of the insulating partition plate 38 made of resin, the insulating partition plate
It is held at 38. The insulating partition plate 38 is horizontally mounted at a position one-third the depth of the top plate 41 of the transformer container 40 filled with insulating oil 39, and the transformer container 40 is divided into an upper room A and a lower room B. It is divided into. The primary / secondary coaxial winding transformer coil 42 is attached to the leg 35b of the leg of the ferrite core 35 which is not in contact with the insulating partition plate 38, and its central axis is parallel to the insulating partition plate 38. Has become. In the upper room A partitioned by the insulating partition plate 8, a rectifier circuit having a rectifier diode 33 and a smoothing capacitor 34 is mounted on diode mounts 43 and 44. In the insulating partition plate 38, at a position directly above the transformer coil 42 and at a position outside the core holders 36 and 37 and the diode mounting members 43 and 44, the cross-sectional area of the transformer coil 42 is the same as the whole. Multiple through holes 45, 46
Is divided and provided. The depth of the core holders 36 and 37 is almost the same as the depth of the transformer container 40, and the height is
The depth of the lower chamber B of the insulating partition plate 38 is set to about 60%, and the insulating oil 39 of the lower chamber B is divided between the inside and the outside of the core holders 36 and 37. Further, fin-shaped coolers 47 and 48 for cooling the insulating oil 39 are attached to the outer wall above the insulating partition plate 38 of the transformer container 40. The primary input of the step-up transformer 32 enters from the input terminal 49 and is connected to the primary side of the transformer coil 42. The secondary side of the transformer coil 42 becomes a rectified and smoothed DC high voltage and becomes a ceramic high-voltage insulator 50. Output from

Next, the operation of the above embodiment will be described. In FIG. 2, a gas laser medium is blown into a laser resonator 21 by a blower.
26 through an air supply duct 28 and discharge electrodes 24a,
It is excited by generating a glow discharge between 24b to generate a laser beam. The generated laser light is amplified by reciprocating between the output mirror 22 and the total reflection mirror 23, and finally is amplified by the output mirror 22.
It is taken out from. The gas laser medium whose temperature has risen in the laser resonator 21 is recovered through the exhaust duct 29,
After being cooled by the cooler 27, it is sent again into the laser resonator 21 through the air supply duct 28 by the blower 26.

The output of the low-voltage AC power supply 30 generates an AC voltage by alternately intermittently switching the semiconductor switch elements of the inverter circuit 31, and changes the AC frequency in a frequency region of 1 kHz or more according to the intermittent cycle. The effective voltage is changed. The AC that has been boosted to a high voltage by the step-up transformer 32 is rectified by the rectifier diode 33, smoothed by the smoothing capacitor 34, becomes a high-voltage DC, and is applied to the discharge electrodes 24a and 24b of the laser resonator 21.

In FIG. 1, the ferrite core 35 of the step-up transformer 32 is shown.
And insulating oil 39 heated by the heat of the transformer coil 42
Goes up between the core holders 36 and 37, flows into the upper room A where the rectifier diode 33 and the smoothing capacitor 34 are arranged through the through hole 45 provided in the insulating partition plate 38, and this room A After being cooled by the coolers 47 and 48 at this time, it descends along the inner wall surface of the
Flows into the lower room B through the through hole 46, and circulates through the inside of the transformer container 40 by convection. As a result, it is possible to prevent carbides, dust, and the like floating in the insulating oil 39 from stagnating and adhering to one place and causing insulation breakdown. Further, the transformer coil 42 is disposed in the lower room B filled with the insulating oil 39 in the transformer container 40, and the insulating oil 39 is provided on the insulating partition plate 38.
And fluctuations in the oil level due to the baffles such as the core holders 36 and 37 make it difficult for the dielectric strength to deteriorate due to fluctuations in the oil level and running out of oil, causing dielectric breakdown and lowering the output voltage. Can be prevented.

As described above, according to the embodiment, the inside of the transformer container 40 filled with the insulating oil 39 is vertically divided by the insulating partition plate 38 having the through holes 45 and 46, and the rectifier circuit is disposed in the upper room A. Since the step-up transformer is arranged in the lower room B, the step-up transformer 32 and the rectifier circuit can be mounted in the same transformer case 40, the power source can be reduced in size, and the movement of the oil level can be reduced by the insulating partition plate 38. Since it is blocked, it is possible to prevent the dielectric breakdown voltage from deteriorating due to fluctuations in the oil level or running out of oil, causing dielectric breakdown and lowering the output voltage.

As described above, according to the gas laser device of the present invention, the step-up transformer and the rectifier circuit are mounted in a transformer container filled with insulating oil, and the insulating partition plate having a through hole is provided in the insulating oil. Since the step-up transformer is arranged below the insulating partition plate and the rectifier circuit is arranged above, the high-voltage power supply can be downsized and the output voltage is prevented from becoming unstable, thereby stabilizing the laser light output. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a step-up transformer in one embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a gas laser device in one embodiment of the present invention, and FIG. FIG. 4 is a schematic configuration diagram showing an example of a conventional gas laser device. 21 ... laser resonator, 22 ... output mirror, 23 ... total reflection mirror,
24a, 24b discharge electrode, 25 discharge part of gas laser medium, 26 blower, 27 cooler, 28 air supply duct,
29 exhaust duct, 30 low-voltage DC power supply, 31 inverter circuit (low-voltage AC power supply), 32 step-up transformer,
33 …… Rectifier diode, 34 …… Smoothing capacitor, 35 ……
Ferrite core (iron core), 35a, 35b ... leg, 36, 37 ...
Core holder, 38 ... Insulating partition plate, 39 ... Insulating oil, 40 ...
... Transformer container, 41 ... Top plate, 42 ... Transformer coil,
43,44 …… Diode mounting bracket, 45,46 …… Through hole, 47,48
... cooler, 49 ... input terminal, 50 ... high-voltage insulator, A ...
Upper room, B ... Lower room.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuzo Yoshizumi 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigeki Yamane 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (2)

(57) [Claims] 1. A gas laser apparatus for generating a laser beam by exciting a gas laser medium in a laser resonator by discharge of a discharge electrode connected to a high voltage power supply, wherein the high voltage power supply is capable of changing an effective voltage. A low-frequency AC power supply having a frequency of 1 kHz or more includes a step-up transformer and a rectifier circuit, and the step-up transformer and the rectifier circuit are mounted in a transformer container filled with insulating oil, and the insulating partition plate having a through hole is insulated. A gas laser device provided in oil, wherein the step-up transformer is arranged below the insulating partition plate, and the rectifying circuit is arranged above the insulating partition plate. 2. The coil of the step-up transformer is of a primary / secondary coaxial winding, the core is held so that the center axis of the coil is parallel to the insulating partition plate, and the leg of the iron core to which the coil is not attached is provided. The gas laser device according to claim 1, wherein a leg is held on the insulating partition plate.