JPH1056222A - Gas laser oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas laser oscillator conducting laser beam machining of high quality, while pressure pulses of a laser gas are prevented. SOLUTION: An excellent vibrating pipe such as a bellows 11 to which a vibration-isolating member 12 converting a vibration energy to a thermal energy is fitted is interposed in a gas circulating path interconnecting an optical resonator and a blower 1 circulating a laser gas in this gas laser oscillator. The pressure pulse of the laser gas is absorbed by the vibration isolating-member 12 via the excellent vibrating pipe such as a bellows 11 to obtain a laser beam in which the output pulse is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas laser oscillating device for reducing laser output fluctuations due to laser gas pressure fluctuations.

[0002]

2. Description of the Related Art A conventional gas laser oscillation device will be described below. FIG. 4 shows the structure of a conventional gas laser oscillation device. In FIG. 4, reference numeral 1 denotes a blower, 2 denotes a laser discharge tube, 3 and 4 denote electrodes 3, 4, and 5 disposed near the laser discharge tube 2, high-voltage power supplies connected to the electrodes 3 and 4, 6 denotes a discharge space, 7 Is a total reflection mirror, 8 is a partially transmission type reflection mirror, 9 is a gas cooler, and 10 is a gas circulation path using a metal pipe.

The operation of the gas laser oscillating device configured as described above will be described. First, blower 1
The laser gas is forcibly circulated to the laser discharge tube 2 through the gas circulation system path 10. At this time, a glow discharge is generated in the discharge space 6 from the electrodes 3 and 4 connected to the high voltage power supply 5. The laser gas excited by the glow discharge oscillates and the laser beam is amplified while reciprocating between the total reflection mirror 7 and the partial transmission type reflection mirror 8 to be in a resonance state. From this resonance state, a part of the laser beam is taken out of the laser resonator as a laser beam from the partially transmitting reflection mirror 8, and this laser beam has been used for metal processing such as metal cutting and welding.

[0004]

However, in the above-described conventional configuration, when the laser gas is circulated by the blower 1, the impeller or the rotor is rotated to circulate the laser gas by the blower 1, so that the laser gas is sucked and pushed. It was acting to put out. As described above, the blower 1 forcibly circulates the laser gas by alternately repeating the intake and exhaust of the laser gas. However, the laser gas pressure (Torr) for the intake and exhaust is changed as shown by a curve (a) in FIG. Pulsation occurred. Due to the pulsation of the laser gas pressure (Torr), the pressure distribution in the laser discharge tube 2 became non-uniform, and the discharge was concentrated on the low-pressure portion and became unstable. For this reason, since the output of the laser beam largely depends on the discharge state, the output pulsated unstablely by about 10% in synchronization with the pressure fluctuation of the laser gas.
As described above, since the output of the laser beam pulsates unstablely, there is a problem that the cut surface roughness (μm) is deteriorated in the case of metal cutting. That is, as shown in FIG. 6, the cut surface roughness (μm) is related to the output fluctuation rate (%) of the laser beam, and tends to be significantly deteriorated when the output fluctuation rate (%) of the laser beam is 5% or more. Was. Also, as shown in FIG. 7, the laser output fluctuation rate (%) is proportional to the laser gas pressure fluctuation rate (%). The rate (%) had to be less than 5%. Conventionally, the gas circulation path 10 was used for the connection part, but the natural frequency (Hz) was not considered at all. For example, the pressure pulsation frequency (Hz) / Natural frequency of pipe (Hz)
Since the ratio of 2 existed, the pressure pulsation of the laser gas could not be transmitted to the pipe.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. It is an object of the present invention to provide a gas laser oscillating device capable of suppressing a pulsation of a laser beam and obtaining a high-quality processed surface by suppressing a pulsation of a laser gas. Aim.

[0006]

In order to achieve this object, a gas laser oscillating apparatus according to the present invention is provided with an anti-vibration material for converting vibration energy into heat energy in a gas circulation system connecting a blower and an optical resonator. It has a good vibration pipe.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above construction, the present invention has a construction in which a good vibration pipe fitted with an anti-vibration material for converting vibration energy to heat energy is interposed in a gas circulation path connecting a blower and an optical resonator. And

The pressure pulsation generated in the laser gas has a frequency (Hz) that is an integral multiple of the rotation frequency (Hz) of the impeller or the rotor inside the blower 1. A device used as a laser gas circulation system has a characteristic called a natural frequency (Hz). This natural frequency (Hz) is a value determined by the spring constant and weight of the metal pipe. At this time, the rate at which the pressure pulsation of the laser gas is transmitted to the metal pipe is called a vibration transmission ratio, and is determined by the pressure pulsation of the laser gas and the natural frequency of the metal pipe. FIG. 2 shows the relationship between the laser gas pressure fluctuation rate (%) and the vibration transmission ratio. In order to reduce the laser gas pressure fluctuation rate (%) to 5% or less in order to obtain a high quality processed surface, the vibration transmission ratio needs to be 1.3 or more. FIG. 3 shows a characteristic diagram of the vibration transmission ratio. According to FIG. 3, in order to make the vibration transmission ratio 1.3 or more, the value of the pressure pulsation number (Hz) of the laser gas / the natural vibration number (Hz) of the pipe is set to be in the range of 0.5 to 1.3. For example, the pressure pulsation of the laser gas can be effectively transmitted to the metal pipe.

Therefore, in the present invention, the good vibration pipe connecting the blower and the optical resonator has a pressure pulsation frequency (Hz) / natural frequency (Hz) of the laser gas of 0.5 to 0.5.
If the range is 1.3, the vibration transmission ratio can be increased to 1.3 or more as shown by the hatched area in FIG. 3 and the pressure pulsation of the laser gas can be effectively transmitted to the good vibration pipe. In this case, the vibrating pipe itself vibrates due to the transmitted pressure pulsation, and this vibration tends to generate a loud noise. However, it is necessary to attach an anti-vibration material that converts vibration energy into heat energy around the vibrating pipe. Thus, the vibration of the good vibration pipe can be absorbed by the anti-vibration material and the generation of noise can be prevented.

[0010] As described above, the pressure pulsation of the laser gas is finally absorbed by the vibration-proof material that converts vibration energy into heat energy through the good vibration pipe, and the vibration-proof material converts the vibration energy into heat energy. The pressure pulsation of the laser gas is reduced, and the laser gas pressure (Torr) is stabilized as compared with the previous time as shown by the curve (b) in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

In FIG. 1, reference numerals 1 to 10 are the same as those in the conventional example, and the description is omitted.

In FIG. 1, the ratio of the pressure pulsation frequency (Hz) / natural frequency (Hz) of the laser gas is 0.5 to 1.3.
In the present embodiment, a bellows 11 is used as a good vibration pipe having a range of (1), and a sheet-like rubber 12 having high viscosity is used in the present embodiment as an anti-vibration material for converting vibration energy into heat energy.

The operation of the gas laser oscillation device having the above configuration will be described. First, a laser gas with suppressed pulsation is circulated through the bellows 11 by the blower 1 through the laser discharge tube 2 at a high speed, and a discharge is generated in the discharge space 6 from the electrodes 3 and 4 connected to the high-voltage power supply 6. The laser gas excited by the discharge is brought into a resonance state by the total reflection mirror 7 and the partial transmission type reflection mirror 8, and the vibration of the bellows 11 is suppressed by a highly viscous sheet-like rubber. A laser beam with little pulsation can be obtained.

As described above, the gas laser oscillating device according to the present embodiment can generate a laser beam with little pulsation, so that an excellent effect of obtaining high quality processing can be obtained.

As another embodiment of the present invention, porous or plastic rubber can be used as the sheet-like rubber 12 having high viscosity. Further, similar effects can be obtained by using cloth other than the sheet rubber.

[0017]

As described above, according to the present invention, a high-vibration pipe provided with an anti-vibration material for converting vibration energy into heat energy is used in a gas pipe line connecting a blower and an optical resonator. Accordingly, the pulsation of the laser beam due to the pulsation of the laser gas is remarkably suppressed, and an excellent effect of realizing an excellent gas laser oscillation device capable of performing high-quality laser processing is achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a gas laser oscillation device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a laser gas pressure fluctuation rate (%) and a vibration transmission ratio.

FIG. 3 is a diagram of a vibration transmission ratio characteristic.

FIG. 4 is a schematic configuration diagram of a conventional gas laser oscillation device.

FIG. 5 is a comparative characteristic diagram showing a temporal change of a laser gas pressure.

FIG. 6 is a characteristic diagram of a cut surface roughness (μm) with respect to a variation in laser beam output.

FIG. 7 is a characteristic diagram of a laser output fluctuation rate (%) with respect to a laser gas pressure fluctuation rate (%).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blower 11 Bellows (good vibration pipe) 12 Seismic isolation material

Claims (2)

[Claims] 1. A gas laser oscillating device comprising a blower for circulating a laser gas and an optical resonator for exciting the laser gas by discharge and generating a laser beam, wherein the gas circulating system connects the blower and the optical resonator. A gas laser oscillating device with a high-vibration pipe attached to a road with an anti-vibration material that converts vibration energy into heat energy. 2. A good vibration pipe has a value of (pressure pulsation frequency (Hz) of laser gas / natural frequency (Hz) of pipe) of 0.
2. The gas laser oscillation device according to claim 1, wherein the vibration transmission ratio is not less than a range of 5 to 1.3.