JPS58182887A - Laser oscillator - Google Patents

Abstract

PURPOSE:To prevent the decrease in the long term reliability of a laser oscillator due to the mixture of oil mist in gas circulating system by controlling to exhaust gas in the gas circulating system from an oil tank of a circulating pump or from the gas circulating system at the leakage time. CONSTITUTION:A leakage valve 8 is closed by a sequence controller 11, the operation of an exhaust pump 6 is started, the valve 7 is opened, and gas in the system is evacuated. Since the gas is exhausted through an oil tank 35, it is not necessary to contaminate in the system with oil mist. A gas supply valve 9 is closed at the stopping time, and a circulating pump 3 is stopped. The valve 8 is opened, and the valve 7 is gradually closed, and the pump 6 is stopped. When the leakage valve 8 is opened, gas (air) is introduced into the system, but since the valve 9 is closed so as to maintain the state that the pressure in the oil tank 35 is lower than the gas pressure in the pump, oil mist in the tank 35 does not reversely flow into the gas circulating system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas circulation type laser oscillator.

FIG. 1 shows a gas circulation system of a conventional gas circulation type laser oscillator. Laser oscillation is performed within an optical resonator including a laser tube 1. 2 is a heat exchanger for cooling the high temperature gas heated by discharge excitation. 3 is a circulation pump, and the heat of compression is cooled by a heat exchanger 4. The laser gas returned to the base state by cooling is supplied to the laser tube 1 again through the pipe 6, and continuous laser oscillation is maintained. 7
゜8.9 is operated with pulp and operated as a sealed cut-off type, or a part of the constantly circulating gas is discharged from the exhaust pump 6, and fresh gas is supplied from the container 1o to replenish it, and the system It is operated while maintaining the internal gas pressure at a constant angle of 31 degrees.

When starting and stopping the operation of the laser oscillator, the leak valve 8 and the gas supply valve 9 are closed, the valve 7 is opened, and the exhaust pump 6 is operated. A mixed gas is supplied into the vacuum system evacuated by the exhaust pump 6 through the valve 9 to an appropriate pressure, and laser oscillation is started. When the operation is stopped, the gas supply is stopped by the valve 9, the valve 7 is closed, the leak valve 8 is opened, and the operation of the exhaust pump 6 is stopped.

By the way, the circulation pump 3 is equipped with an oil tank for lubricating and cooling the sliding surfaces of the bearings, shaft soles, timing gears, etc., so this oil may leak into the system in the form of a mist or through the shaft seals, causing laser gas. The drawback is that it contaminates the air and reduces output. These will be explained in detail with reference to FIG.

Figure 2(b) is a sectional view of the circulation pump section, and Figure 2(a)
A cross section taken along line AA' of the side view shown in FIG.

30 is a circulation pump body, 31 is an emperor, and 132 is a shaft seal called a labyrinth seal.

33 is a bearing, 34 is a timing gear for rotating the two emperors at a constant speed, 35 is an oil tank, and 36 is lubricating oil. 37 is a vacuum-tight seal, 38 is an oil introduction core, and 39 is a drive shaft.

Such conventional devices have the following drawbacks.

■ At the start of operation and during the initial exhaust, the gas (air) in the oil tank 35 is exhausted through the gap between the bearing 33 and the labyrinth seal 32, so the oil adhering to these surfaces becomes a mist and gas Enter the circulatory system. Although an airtight ring 37 is provided on the drive shaft side of the trench, an oil film is formed on the sliding surface, and the oil on the surface also enters the system and contaminates the laser gas. This oil mist contamination is shown by solid arrows.

■ When the operation is stopped, on the contrary, oil mist suddenly flows into the oil tank 35 from the emperor 31 side in the gas circulation system through the narrow gap between the labyrinth seal 32 and the bearing 33, creating oil mist in the oil tank 36 as shown by the dotted arrow. let It takes several minutes to tens of minutes for the gas containing a large amount of oil mist to sink and return to the oil tank.
If the operation is restarted immediately after it has been stopped, a large amount of oil will get mixed into the system.

During laser oscillation, there is no difference in force between the oil tank 35 and the case of the Emperor 31, so there is no negative effect, but if the operation is stopped and started repeatedly for a long period of time, the output will be low due to laser gas contamination, and the life of the optical components will be reduced. There are many negative effects such as a decrease in

The present invention provides a laser oscillator having a gas circulation system that solves these drawbacks. One embodiment will be described below with reference to the drawings.

FIG. 3 shows a gas circulation system of a gas circulation type laser oscillator in one embodiment of the present invention.

Components that are the same as those in FIG. 1 are given the same reference numerals, and their explanation will be omitted.

In FIG. 3, the system is evacuated from a part of the circulation pump 3, and leakage occurs at the time of shutdown through a leak valve 8 provided in any part of the piping within the system.

Also, for evacuation after rough evacuation 61 ゛ has been completed by the exhaust pump 6, or for evacuation while the pressure in the piping 63 of the circulation pump 3 is always maintained lower than the pressure in the empeller container in the system. An auxiliary exhaust pipe 54 may also be provided.

Exhaust pump 6, circulation pump 3. The operation of valves 7 and 8 is controlled by a sequence controller 11 so that oil mist in the oil tank does not mix into the gas circulation system. Reference numeral 12 indicates command signals for the valves 7.8.9, the circulation pump 3, and the exhaust pump 6.

FIG. 4(b) is a sectional view of the vicinity of the gas circulation pump 3 of the present embodiment shown in FIG.
' Shows a cross section at '. The auxiliary exhaust pipe 54 is omitted.

Dedicated piping 5 that is independent of the gas circulation system piping 5 (shown in FIG. 3) runs from the oil tank 35 on both sides of the circulation pump body 30.
Oil mist is discharged from the exhaust pump 6 through 3 to the outside of the gas circulation system. 7 is an exhaust pipe valve, and 8 is a leak valve. 31 is an emperor, 36 is lubricating oil, and 39 is a drive shaft. The electromagnetic valves 7 and 8, the exhaust pump 6, and the circulation pump 37 lL-,' are controlled by signals from the sequence controller 11 in the following order.

(2) The leak valve 8 is closed and the exhaust pump 6 starts operating, and the valve 7 is opened to exhaust the system from the oil tank 35. Since the gas is exhausted through the oil tank 35 and released into the atmosphere, there is no fear of contaminating the system with oil mist.

(2) The operations from introducing laser gas to laser oscillation are the same as in the conventional example and will therefore be omitted.

(2) When the operation is stopped, the gas supply valve 9 shown in FIG. 3 is similarly closed by the sequence controller 11, and the rotation of the emperor 31 of the circulation pump 3 is stopped. Next, the leak pulp 8 opens and starts leaking, and the valve 7
is gradually closed, and the operation of the exhaust pump 6 is stopped. I
Gas (air) is added to the system by opening the J+ valve 8.
However, as the valve 7 is closed according to the command from the sequence controller 11 so that the pressure in the oil tank 36 is always maintained lower than the gas pressure in the circulation pump, the oil mist in the oil tank 35 is will not flow back into the gas circulation system.

Incidentally, in order to maintain the apparatus without leaking the inside of the system, it is sufficient to close the valve 7 and stop the exhaust pump 6.

As described above, according to this embodiment, contamination in the gas circulation system due to oil mist entering from the circulation pump can be reduced as much as possible, and stable output can be maintained for a long period of time.

FIG. 5 shows a second embodiment of the invention. The same parts as in the first embodiment shown in FIG. 3 are given the same numbers. In this embodiment, in order to save gas consumption, the gas released into the atmosphere from the exhaust pump 6 is regenerated and used, and as shown in the figure, a gas regeneration system piping 65 is provided at the rear stage of the exhaust pump 6. , the oil mist released from the circulation pump 3 and the exhaust pump 6 is completely removed by the oil mist filter 13,
This is achieved by subsequently regenerating carbon dioxide, which has been decomposed into carbon monoxide and oxygen through the oxidation catalyst 14, into carbon dioxide and returning it to the gas circulation system. 15, 16 and 17 are valves.

The 9-vano catalyst was conventionally installed on the low-pressure side of the front stage of the exhaust pump 6, but in this embodiment it is installed after passing through the oil mist filter on the high-pressure side of the rear stage. It is better to install this on the high pressure side.
This is because the amount of gas molecules that come into contact with the catalyst is large and a highly efficient catalytic action can be obtained.

The order of operations in this embodiment is as follows.

- At the start of operation, leak valve 8 and valve 9.16 are closed, and valve 17.16 is opened.

Next, the exhaust pump 6 starts operating, and the valve 7 is opened to exhaust the gas in the gas circulation system from the pipe 53. At this time, in order to increase the exhaust speed, a pipe 64 is provided.
It is also possible to exhaust the air at the same time as the oil tank 35 shown in Figure 4. , is performed according to a command 12 from a sequence controller 11.

(2) Gas is introduced from the gas container 1Q after evacuation by opening the valve 9, and an optimum gas pressure is maintained by controlling the opening amount of the valve 9.

Laser excavation is started in this state.

In operation in the gas regeneration system, by closing valves 9 and 17 and opening valve 15, the gas exhausted by exhaust pump 6 passes through oil mist filter 13 and catalyst 14, passes through valve 16, and is returned to the system. It is done.

(2) To stop the operation, the operation of the circulation pump 3 is stopped, the valve 15 is closed, and the valve 17 is opened. Next, while gradually opening the leak valve 8, the valve 7 is gradually closed, and after the leak has completely stopped, the operation of the exhaust pump 6 is stopped. The valve 16 is provided for the purpose of shielding the catalyst from the atmosphere in order to protect it when the operation is stopped for a long period of time.

These operations from start to stop of operation are automatically performed by a command signal 12 from a sequence controller 11. If the device is to be maintained without leaking into the system, the valve 16 is closed, the operation of the exhaust pump 6 is stopped, and the valve 12 is opened.

Conventional gas regeneration methods include extracting gas from a part of the gas circulation system piping using an exhaust pump, passing it through an oil mist filter and catalyst, and returning it to a part of the gas circulation system piping, or directly reproducing gas within the gas circulation system. Because it was one of those systems that included a catalyst in the tank, it was completely defenseless against the oil mist emitted from the circulation pump. As a result, the inside of the system becomes contaminated due to long-term operation, resulting in a decrease in output due to deterioration of optical components, etc.

In the embodiment shown in FIG. 5, all the oil mist generated from the gas circulation pump 3 and exhaust pump 6, which are oil mist generation sources, passes through the oil mist filter 13, so that even during gas regeneration operation, the oil mist is circulated through the gas circulation. Contamination within the system is extremely rare.

Further, in the present invention, by setting the sequence controller 11 as shown below, it is possible to save gas consumption without using the catalyst 14 shown in FIG. 5. An example of this will be explained using FIG.

In Figure 3, after starting laser oscillation, valves 7 and 9
are closed at the same time and operated for a certain period of time, for example, two hours, and then valves 7 and 9 are simultaneously opened for a certain period of time, for example, five minutes while maintaining laser oscillation to replenish fresh gas and prevent a drop in output. Since the exhaust pump 6 does not exhibit predetermined characteristics immediately after starting, it is necessary to start operation, for example, 6 minutes before opening the valve. The operation of these valves and exhaust pump 6 is a must!・Command signal 1 from Row 211
2, it is automatically operated according to a predetermined program. By adopting such an operation mode, gas consumption can be greatly reduced, laser oscillation can be maintained continuously for a long period of time, and the inside of the father's line can be kept clean.

As described above, the present invention is configured such that gas in the gas circulation system of a laser oscillator is exhausted from the oil tank of the circulation pump, and conversely from within the gas circulation system in the event of a leak, and various valves are controlled by a sequence controller. By controlling this, oil mist from the oil tank of the circulation pump, which is a source of contamination, gets mixed into the gas circulation system.

This can prevent deterioration in long-term reliability. When performing gas regeneration to save waste gas, the above configuration is basically used, and an oil mist filter and catalyst are installed on the discharge side of the exhaust pump to easily return the regenerated gas that does not contain oil mist into the gas circulation system. can be achieved.

Furthermore, even without a gas regeneration device, continuous oscillation can be maintained for a long period of time by periodically replenishing fresh gas through automatic operation of valves and pumps.

[Brief explanation of drawings]

Figure 1 is a conceptual diagram showing the gas circulation system section of a conventional gas circulation type laser oscillator, Figure 2 (-) is a right side view of the circulation pump section, Figure 3 (b) is an enlarged sectional view of the same, and Figure 3 Figure 4 is a conceptual diagram showing the gas circulation system of a gas circulation laser oscillator according to an embodiment of the present invention; Figure 4) is a side view of the circulation pump;
b) is a sectional view of the same, and FIG. 6 is a conceptual diagram showing a gas circulation system section including a gas regeneration system of another embodiment of the gas circulation type laser oscillator of the present invention. 1-...laser tube, 2-heat exchanger, 3-...circulation 14
Part pump, 4... - heat exchanger, 5 - Piping, 6-...
Exhaust pump, 7,8,9,12,15.16--Valve, 10 Gas container, 11-Sequence controller, 12 Command signal, 13--Oil mist filter, 14--Catalyst, 53--Exhaust Piping for use. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure J Figure 2 Figure 3! Figure 4 (4)

Claims (3)

[Claims] (1) A laser tube, a circulation piping connected to the laser tube, and a circulation pump provided in a part of the circulation piping, and the circulation pump circulates the medium gas through the circulation piping. An exhaust pump is provided in a part of the oil tank of the circulation pump via an exhaust pipe, a leak pipe is provided in a part of the circulation pipe, and the medium is further connected from the gas supply source to the circulation pipe. A gas supply pipe for supplying gas is provided, and a sequence controller is provided for controlling at least valves provided in the circulation pump, the exhaust pump, the exhaust pipe, the leak pipe, and the gas supply pipe. Laser oscillator. (2) Claim 1, characterized in that gas regeneration means is provided downstream of the exhaust pump connected to the exhaust pipe.
Laser oscillator described in section. 2be (3) A patent claim characterized in that, after laser oscillation, a sequence controller is set to intermittently operate a valve provided in an exhaust pipe and a pulp provided in a gas supply pipe. The laser oscillator according to the range 1 above.