JP3259591B2 - Laser oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator, and more particularly, to a laser oscillator having improved reliability.

[0002]

2. Description of the Related Art FIG. 15 shows, for example, Japanese Patent Publication No. 63-640.
FIG. 17 is a perspective view showing a configuration of an oscillator main body of a conventional laser oscillator described in Japanese Patent Publication No. 73-73. In the figure, 1 is an oscillator main body, 2 is a housing for enclosing a laser medium gas, 3 is a pair of upper and lower discharge electrodes, 4 is a duct forming a laser gas flow path, 5 is a heat exchanger, 6 is a medium. Blower as gas circulation means, 7 is a partial reflection mirror, 8 is a total reflection mirror, 7a
Is a laser beam emitting means including a partial reflecting mirror 7, 8a is a laser beam reflecting means including a total reflecting mirror 8, and 9 is a laser beam.

FIG. 16 is a configuration diagram showing the configuration of a conventional laser oscillator. In the figure, 10 is a cooling device, 23 is an inlet port of a cooling medium for cooling the heat exchanger 5, 24 is an outlet port of a cooling medium for cooling the heat exchanger 5, 25 or 2
Numeral 6 denotes an inlet port or an outlet port of a cooling medium for cooling the heat exchanger 5 provided in the housing 2, 27 and 28 denote branch points of pipes, and 29 and 30 denote heat exchange from the inlet port 25 or the outlet port 26, respectively. A pipe leading to the vessel 5, 33 and 34 are an inlet port or an outlet port of a cooling medium for cooling the discharge electrode 3 provided in the housing 2, and 31 and 32 are from the inlet port 33 or the outlet port 34 to the discharge electrode 3, respectively. The pipes 29 and 30 are connected from the branch points 27 and 28 to the inlet port 33.
Or pipes leading to the outlet port 34, pipes 31 and 32 leading from the branch point to the inlet port 33 or the outlet port 34,
21 and 22 are pipes between the cooling device 10 and the oscillator body 1,
1 is a chiller, 12 is a tank, 13 is a tank return, 14 is a pump, 15 is an ion exchanger, 16 is a tank outlet, 1
Reference numerals 7 and 18 denote pipes connecting the ion exchanger 15 and the pump 14. 35 is a pipe connecting between the pair of discharge electrodes 3.

FIG. 17 is a structural view of the heat exchanger 5 shown in FIG. 16, and FIG. 18 is "A" in the heat exchanger 5 shown in FIG.
19 is an enlarged cross-sectional view of a main part of FIG. 19, FIG. 19 is an enlarged cross-sectional view of a main part of "B" part in the heat exchanger 5 shown in FIG.
FIG. 4 is an enlarged sectional view of a main part of a “C” part in FIG. In the figure, 5a is a fin, 5b is a copper tube, 23a and 24a are headers, 23b and 24b are header feet, 5c is a U-bend tube, 5c
d is a brazing material such as a flux type. Heat exchanger 5
Are fins 5a and copper tubes 5b, headers 23a and 24a,
It is constituted by header legs 23b and 24b and U-bend tube 5c.

Next, the operation of the conventional laser oscillator will be described. The housing 2 has a pair of discharge electrodes 3 for exciting the laser medium gas by generating a discharge, a blower 6 for circulating the laser medium gas, and a heat exchanger 5 for cooling the laser medium gas. When the laser medium gas passes between the pair of discharge electrodes 3, it is excited into a state where laser oscillation is possible. At least one of the discharge electrodes 3 has a dielectric layer on the surface, and is supplied with power from an AC power supply (not shown) to generate an AC discharge. The laser medium gas heated to a high temperature by the discharge enters the heat exchanger 5 through the duct 4, is cooled, and circulates through the blower 6 in the direction of arrow A. The optical path formed by the resonator mirror composed of the partial reflecting mirror 7 included in the laser beam emitting means 7a and the total reflecting mirror 8 included in the laser beam reflecting means 8a arranged in the longitudinal direction of the housing 2 is caused by electric discharge. The laser medium gas passes through the excited region in the excited state.

[0006] The laser beam 9 reflected by the total reflection mirror 8 reaches the partial reflection mirror 7, a part of the laser beam 9 reaching the partial reflection mirror 7 is output to the outside as it is, and the rest passes through the reverse route. To the total reflection mirror 8, and the above process is repeated. The laser beam 9 is thus amplified while repeatedly passing through the excitation region, and is output from the partial reflecting mirror 7 to the outside.

In the operation of the laser oscillator, cooling water supplied from the cooling device 10 for cooling the heat exchanger 5 and the discharge electrode 3 is required. Cooling water is supplied from the cooling device 10 to the oscillator main body 1. The lower the temperature of the laser medium gas passing through the discharge electrode 3, the better the efficiency of laser oscillation. Therefore, the temperature of the cooling water for cooling the heat exchanger 5 is preferably low. The lower the temperature of the dielectric of the discharge electrode 3, the higher the dielectric breakdown voltage and the higher the reliability. For this reason, the temperature of the cooling water for cooling the heat exchanger 5 and the discharge electrode 3 is set to a low temperature that does not freeze.
The cooling water for cooling the discharge electrode 3 is the same system cooling water.

[0008] Cooling water is supplied to the oscillator main body 1 from the cooling device 10 through a pipe 21. The cooling water is split at a branch point 27 of the pipe 21, and the cooling water entering the housing 2 from an inlet port 25 provided in the housing 2 passes through the pipe 29 and passes through the heat exchanger 5.
, And exits the housing 2 again through the outlet port 26 provided in the housing 2 through the pipe 30 to reach the branch point 28 of the pipe 22. On the other hand, the cooling water that has entered the housing 2 from the inlet port 33 provided in the housing 2 enters the lower discharge electrode 3 through the pipe 31 and enters the upper discharge electrode 3 through the pipe 35. Thereafter, the air exits the housing 2 again through the outlet port 34 provided in the housing 2 through the pipe 32, and reaches the branch point 28 of the pipe 22. After that, the cooling water returns from the oscillator main body 1 to the cooling device 10 through the pipe 22.

The cooling water returned to the cooling device 10 is cooled by the chiller 11 and enters the tank 12 through the tank return 13. The cooling water is released from the tank return port 13 into the gas phase in the tank 12 so as not to be mixed again with the cooling water flowing out of the tank 12 from the tank outlet 16. Tank 12
The water in the cooling device 1 passes through a pipe 21 by a pump 14.
Get out of zero. In this manner, the cooling water circulates through the cooling water system to form a first cooling water circulation circuit.

Further, pipes 17, 18 provided near the cooling water inlet / outlet of the pump 14 and connected to the ion exchanger 15 are provided.
Constitutes a second cooling water circulation circuit. The cooling water that has passed through the second cooling water circulation circuit is purified into water by the ion exchanger 15 (mixed with a positive and an anion exchange agent), and the electrical conductivity is reduced. The electric conductivity of the cooling water flowing through the first cooling water circulation circuit decreases with time,
The state where the electric conductivity is small is maintained. Cooling water having low conductivity is necessary to cool the discharge electrode 3 to which a high voltage is applied.

Next, the heat exchanger 5 will be described. Since the heat exchanger 5 of the laser oscillator is inside the housing 2, the required conditions are very severe. In order to obtain an effective output from the laser oscillator, the dew point in the housing 2 needs to be kept at -30 ° C or lower. For this purpose, water leakage as much as water vapor is not allowed, and it is not allowed that the heat exchanger 5 has a hole such as a pinhole. A heat exchanger of the type that cools with normal water 5
Considering that such a hole does not pose a problem in the use environment, the corrosion resistance required for the heat exchanger 5 for the laser oscillator is very high.

The high-temperature laser medium gas flows between the fins 5a of the heat exchanger 5, and the fins 5a are provided in contact with the copper tubes 5b through which the cooling water flows, so that the copper tubes 5b pass through the fins 5a. Then, the heat absorbed from the high-temperature laser medium gas is absorbed by the cooling water.

The cooling water supplied to the heat exchanger 5 enters through the inlet port 23 and the inlet side header 23a, is branched there, flows through the copper pipe 5b through the header foot 23b, and flows through the heat exchanger 5. U-bend tube 5 on the opposite side of entrance side header 23a
The direction is changed by c, and the flow again reaches the outlet port 24 from the outlet side header 24a through the copper tube 5b and the header foot 23b.

The headers 23a, 24a of the heat exchanger 5,
The joints of the header feet 23b, 24b, the copper tube 5b, and the U-bend tube 5c are joined by brazing material 5d by brazing. An example of the structure will be described in detail with reference to FIG. The joint between the header feet 23b, 24b and the copper tube 5b is filled with a brazing material 5d.

In the brazing, the brazing operation is usually performed using a flux. If the flux remains after brazing, it causes corrosion of the pipe and must be completely removed. Laser oscillator heat exchanger 5
Due to its complicated structure, it is very difficult to completely remove the flux after the brazing step, especially inside the tube. Therefore, as the brazing material 5d, a non-flux type material that can be used without using flux at the time of brazing is used. As the non-flux type brazing material 5d, there is a phosphor copper brazing, and the brazing of the heat exchanger 5 of the laser oscillator uses the phosphor copper brazing.

However, in the case where the copper tube 5b brazed by the phosphor copper brazing is continuously used in water having low electric conductivity, corrosion starts around the brazing portion, and the corrosion gradually starts. And a phenomenon progressing at the boundary between the copper tube 5b and the copper tube 5b was observed. Due to this corrosion,
For those used for about 10 years, holes are formed in the heat exchanger 5, cooling water leaks into the housing 2, the amount of water in the housing 2 becomes large, and the output is let alone and laser oscillation is impossible. There was a risk of falling into.

This corrosion is presumed to be initiated by phosphorus contained in the brazing material 5d. This can be explained by the following reaction equation. First, phosphorus reacts with water,
Generates phosphoric acid. P + 4H2 O → H2 PO4− + 6H ++ 5e− The action of this phosphoric acid destroys the oxide film on the copper tube. CuO + 2H + → Cu2 ++ H2O As a result, the copper in the copper tube 5b is exposed to water, and the copper is corroded. Cu + H2 O → CuO + 2H ++ 2e− Cu → Cu2 ++ 2e− When oxygen is present in water, a reduction reaction consuming electrons of the above formula occurs. This accelerates corrosion. O2 + 2H2 O + 4e- → 4OH-

Therefore, it was presumed that the progress of the corrosion could be slowed by reducing the amount of dissolved oxygen in the cooling water, and was confirmed by the present inventors. In addition, this type of corrosion is less likely to be induced when the oxide adheres to the inner surface of the copper tube 5b. However, in pure water having low electric conductivity, the oxide hardly adheres to the inner surface of the copper tube 5b, and It is likely to be provoked in

[0019]

However, in the configuration of the conventional laser oscillator, the cooling water for cooling the heat exchanger 5 is pure water having a small electric conductivity, and the brazing filler metal contains phosphorus. It is difficult to prevent the induction of corrosion. Also,
It is difficult to keep the amount of dissolved oxygen low when corrosion is induced. The cooling water that has returned to the cooling device 10 is discharged into the tank 12 from the tank return port 13, but there is air in the gas phase of the tank 12, and oxygen dissolves into the cooling water from the water surface in the tank 12. . Therefore, it is extremely difficult to keep the dissolved oxygen content of the cooling water at a level significantly lower than the saturated dissolved oxygen content. Conventional laser oscillators
With such a configuration, there is a possibility that the laser oscillator suddenly becomes inoperable due to water leakage of the heat exchanger 5.

In order to prevent oxygen from dissolving in the cooling water in the tank 12, the technique disclosed in Japanese Utility Model Laid-Open Publication No. 63-86096 responds as follows. FIG. 21 is a schematic view of a tank of a cooling device of a conventional laser oscillator,
This corresponds to the tank 12 of the cooling device 10 in FIG. In the figure, reference numeral 40 denotes a plate-like float formed of a foaming synthetic resin floated by the buoyancy of cooling water.
Although the float 40 has a plate shape, it is necessary to increase the accuracy of the verticality and flatness of the wall surface of the tank 12 in order to prevent a gap from being formed in a portion where the float 40 is in contact with the wall surface of the tank 12. . Further, even if the tank 12 is manufactured with high precision, the float 40 may be stuck on the water or sink under the water surface due to friction between the tank 12 and the plate-shaped float 40, and the In order to prevent oxygen from dissolving into the cooling water in the air, the air shutoff state could not be ensured.

There is also a technique using an oxygen deoxygenator 60 to remove oxygen from the cooling water in the tank 12. For example, there is a corrosion prevention system in a building water supply system described in Japanese Utility Model Laid-Open No. 4-25860. This technology prevents the generation of rust itself due to oxidation of the piping,
Regarding the prevention of corrosion induced by phosphorus contained in the brazing material 5d because an oxide film is not formed in the copper tube due to the use of pure water as in the heat exchanger 5 of the laser oscillator and there is no protection by the oxide film. It is a fundamentally different technology. In particular,
In the water supply system, the water is a disposable system, but the cooling water system of the laser oscillator basically forms a closed loop system, and the purity of the water is very different.

Therefore, the present invention has been made to solve the above-mentioned problems, and has as its object to provide a highly reliable laser oscillator which reduces the amount of corrosion of piping of a heat exchanger. is there.

[0023]

According to a first aspect of the present invention, there is provided a laser oscillator comprising: a tank provided in a circulation path of cooling water for cooling a heat exchanger; A gas supply port is provided in a portion, and an inert gas containing no oxygen is supplied into the tank.

According to a second aspect of the present invention, the cooling water for the heat exchanger and the cooling water for the discharge electrode are separated from each other, and the cooling water for the discharge electrode having low electric conductivity is cooled by the heat exchanger for the heat exchanger. This is performed by a heat exchanger with cooling water.

According to a third aspect of the present invention , in the laser oscillator, a deoxygenating device is provided in a closed circuit of cooling water for cooling the heat exchanger,
In a tank provided in a cooling water circulation path for cooling the heat exchanger, a granular float for shutting off water and air is floated on a water surface in the tank.

According to a fourth aspect of the present invention, there is provided the laser oscillator, wherein the main component is a member in which the cooling water for cooling the heat exchanger is oxidized more upstream than the heat exchanger. Is provided.

The laser oscillator according to claim 5 is configured such that the cooling water passing through the heat exchanger does not come into contact with the brazing portion in the circulation path of the heat exchanger.

According to a sixth aspect of the present invention, there is provided a laser oscillator.
The laser oscillator according to any one of claims 2 to 5 , wherein the tank provided in the cooling water circulation path for cooling the heat exchanger contains no oxygen on the surface of the cooling water in the tank. It supplies inert gas.

[0029]

[Action] In the first aspect, by supplying a gas containing no oxygen in the gaseous phase of the tank to reduce the penetration of oxygen into the cooling water, the cooling water to promote the progress of corrosion of the heat exchanger Reduce the concentration of dissolved oxygen.

[0030] In the second aspect, the circuit of the cooling water for the cooling water and the discharge electrode of the heat exchanger was separated, cooled in the cooling water for a small discharge electrode electrical conductivity includes a cooling water heat exchanger The heat is exchanged between the heat exchangers, and pure water is not used as cooling water to cool the heat exchangers.Oxide adheres to the inner wall of the copper tube and forms a kind of barrier, which suppresses the induction of corrosion. You.

According to the third aspect of the present invention, the deoxidizer provided in the cooling water system for cooling the heat exchanger dissolves in the cooling water which promotes the progress of boundary surface corrosion caused by phosphorus in the heat exchanger. Suppress oxygen concentration. Further, by introducing a gas containing no oxygen into the gas phase above the water surface of the tank, the penetration of oxygen into the cooling water is reduced, and the progress of interface corrosion caused by phosphorus in the heat exchanger is promoted. Reduce the concentration of dissolved oxygen in the cooling water.

According to a fourth aspect of the present invention, a member is provided upstream of the heat exchanger for cooling water for cooling the heat exchanger, and a member which is more easily oxidized than a member constituting the heat exchanger is a main component. The concentration of dissolved oxygen that is consumed and flows into the heat exchanger is suppressed.

According to the fifth aspect , since the cooling water passing through the heat exchanger does not come into contact with the brazing portion in the circulation path of the heat exchanger, not only the corrosion due to the flux but also the corrosion caused by the phosphorus. Does not occur.

In claim 6 , claims 2 to 5
5. The laser oscillator according to any one of 5 , wherein an inert gas containing no oxygen on a surface of the cooling water in the tank is provided in a tank provided in a cooling water circulation path for cooling the heat exchanger. Since it is supplied, the dissolution of oxygen into the cooling water is reduced, and the concentration of dissolved oxygen in the cooling water that promotes the progress of corrosion of the heat exchanger is suppressed.

[0035]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals and symbols as those in the conventional example denote the same or corresponding components as those in the conventional example. In particular, the configuration of the oscillator body 1 and the configuration of the laser oscillator are shown in FIG.
16 is basically the same as the conventional apparatus shown in FIG. 16, and a duplicate description will be omitted here.

FIG. 1 is a schematic view of a tank of a laser oscillator cooling device according to a first embodiment of the present invention, and FIG. 2 is a tank showing another embodiment of the laser oscillator cooling device according to the first embodiment of the present invention. FIG. 17 is a schematic diagram corresponding to the tank 12 of the cooling device 10 in FIG. In the figure, 100 is a granular float floating on the surface of the cooling water in the tank 12. The float 100 is made of a material that does not have air permeability and is lighter than water, such as a foam such as polyethylene or polyolefin. If a large number of the granular floats 100 are used, the tank 1
The water surface of the cooling water can be covered without the problem of friction with the second wall. Therefore, as shown in the conventional example of FIG.
In the plate-like float 40, even if the accuracy of the verticality and flatness of the wall surface of the tank 12 is increased, the float 40 is caught by the friction between the tank 12 and the plate-like float 40 and may sink below the water surface. However, in the present embodiment, the problem of friction with the wall surface of the tank 12 can be solved by using a large number of the granular floats 100, and the water surface of the cooling water can always be covered. Can be. Also, as shown in FIG.
Alternatively, a gap may be provided between the tank and the tank 12, and the water surface of the gap may be covered with the granular float 100.
The configuration of the embodiment shown in FIG. 2 can provide a less expensive device than the configuration of the embodiment shown in FIG.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed facing the inside of the housing 2, and the laser medium gas circulating in the housing 2 Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In the laser oscillator that oscillates the laser light, the inside of the tank 12 provided in the circulation path of the cooling water for cooling the heat exchanger 5 has a structure that cuts off the contact between water and air on the water surface in the tank 12. Granular float 1
00, which can be taken as an embodiment corresponding to the claims. Therefore, the float 100 covering the surface of the cooling water can reduce the contact between the air in the tank 12 and the cooling water, thereby reducing the dissolution of oxygen into the cooling water. Therefore, in the laser oscillator according to the configuration of this embodiment, the amount of dissolved oxygen in the cooling water of the heat exchanger 5 can be reduced, so that the rate of progress of corrosion can be reduced. In addition, the float 100 in the tank 10 at this time may cut off the contact between water and air on the water surface together with the plate-shaped float 40. That is, the float 100 only needs to be configured to block contact between water and air on the water surface in cooperation with other members.

Embodiment 2 FIG. FIG. 3 is a schematic view of a tank of a cooling device of a laser oscillator according to a second embodiment of the present invention, and corresponds to the tank 12 of the cooling device 10 in FIG. In FIG. 3, reference numeral 12 denotes a tank. The tank 12 of the present embodiment includes a tank body 12A for storing cooling water and a lid 12B for sealing an opening of the tank body 12A. 110
Denotes a gas supply port, 111 denotes a drain for cooling water, and 112 denotes a water supply port for supplying replenishing water. From the gas supply port 110, for example, an inert gas containing no oxygen such as nitrogen or argon can be supplied.

Drain receiver 1 for draining drain 111 for cooling water
The lower end is accommodated in 11A. In this way, isolation from the atmosphere is achieved. Further, in the water supply port 112 for supplying the makeup water, when the supply of makeup water is shut off by a valve (not shown), a sealed state can be ensured. Also in the gas supply port 110, when the supply of gas is shut off by the valve, a sealed state can be ensured. Gas supply port 1 during operation of laser oscillator
When an inert gas is blown into the tank 12 from the tank 10, the pressure thereof rises, so that the cooling water drainage drain 111 is formed.
Oxygen such as air contained in the gas phase in the tank 12 is discharged through the drain receiver 111A, and the concentration of oxygen such as air contained in the gas phase in the tank 12 is suppressed to a low level by supplying a predetermined amount or more of gas. The pressure state is maintained. Thus, the amount of oxygen dissolved in the cooling water during operation of the laser oscillator can be significantly reduced.

In the present embodiment, the inside of the tank 12 is sealed and filled with a gas containing no oxygen such as nitrogen or argon. Difficult to seal. Further, when combined with a deoxygenating device including the ion exchanger 15 and the like, the continuous removal of dissolved gas from the cooling water by the vacuum pump by the deoxidizing device means that the gas of the cooling water system is discharged more and more from the cooling water system. So this is tank 1
Sealing 2 means that the gas phase in the tank 12 becomes a vacuum state, which makes sealing more difficult.
Therefore, the inert gas which does not contain oxygen, such as nitrogen or argon, in the tank 12 is normally controlled so that the inside of the tank 12 is sealed and maintained at a predetermined gas pressure.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed to face the inside of the housing 2, and the laser medium gas circulating within the housing 2. Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates a laser beam, an inert gas containing no oxygen is provided on a surface of the cooling water in the tank 12 provided in a circulation path of the cooling water for cooling the heat exchanger 5. And this can be an embodiment corresponding to the claims. The pressure state in which the concentration of oxygen such as air contained in the gas phase in the tank 12 is kept low is maintained. Thus, the amount of oxygen dissolved in the cooling water during operation of the laser oscillator can be significantly reduced. Therefore, the pressure state in which the concentration of oxygen such as air contained in the gas phase in the tank 12 is kept low is maintained, and the dissolution of oxygen into the cooling water can be reduced. Therefore, in the laser oscillator according to the configuration of this embodiment, the amount of dissolved oxygen in the cooling water of the heat exchanger 5 can be reduced, so that the rate of progress of corrosion can be reduced.

Embodiment 3 FIG. FIG. 4 is a configuration diagram showing a configuration of a laser oscillator according to a third embodiment of the present invention. In the figure, 10A is a first cooling device, 10B is a second cooling device, 50 is a heat exchanger, 14
Reference numerals b and 15b denote pumps and ion exchangers provided in the second cooling device 10B, and reference numerals 51 and 52 denote pipes connecting the second cooling device 10B to the oscillator main body 1. The difference from the conventional device is that the cooling device 10 has a first cooling device 10A for cooling the heat exchanger and a second cooling device 10B for cooling the discharge electrode.
The second cooling device 10B is provided with an ion exchanger 15b, but the first cooling device 10B
A has no ion exchanger, the second cooling device 10B has no chiller, and instead has a water-to-water heat exchanger 50, and the secondary side of the heat exchanger 50 constitutes a discharge electrode cooling system. are doing. A pipe on the primary side of the heat exchanger 50 is connected in the middle of a pipe 21 of a heat exchanger cooling system that sends cooling water from the first cooling device 10A to the oscillator body 1. Heat exchanger 5
With 0, the temperature of the cooling water of the discharge electrode cooling system is kept substantially equal to the cooling water of the heat exchanger cooling system.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed facing the inside of the housing 2, and the laser medium gas circulating in the housing 2 Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates a laser beam, a circuit for cooling water for the heat exchanger 5 and a circuit for cooling water for the discharge electrode 3 are separated, and cooling of the cooling water for the discharge electrode 3 having low electrical conductivity is performed by heat. This is performed by the heat exchanger 50 between the cooling water for the exchanger 5 and this corresponds to an embodiment corresponding to the claims.

According to this configuration, the first cooling device 10A
And the discharge electrode cooling system by the second cooling device 10B are provided independently, so that the first cooling device 1
The heat exchanger cooling system using 0A is not pure water, but becomes cooling water of general water quality. Oxide adheres to the inner wall of the copper tube and forms a kind of barrier, so that induction of corrosion is suppressed. When the present invention is carried out, a rust preventive may be used to prevent corrosion. In particular, the conventional apparatus could not be used due to problems such as an increase in electric conductivity due to the rust preventive agent and a decrease in the capacity of the ion exchanger 15, but in the configuration of this embodiment, the first apparatus was not used.
Since the heat exchanger cooling system by the cooling device 10A does not need to be pure water, a rust preventive can be used. Therefore, in the configuration of the cooling system of this embodiment, corrosion can be reduced by mixing a rust preventive agent effective against copper corrosion into the cooling water of the heat exchanger cooling system.

Embodiment 4 FIG. FIG. 5 is a configuration diagram showing a configuration of a laser oscillator according to a fourth embodiment of the present invention, and FIG. 6 is an explanatory diagram of a deoxidizer used in the embodiment of FIG. In the drawing, reference numeral 60 denotes a deoxidizer, 64 denotes a hollow fiber membrane type deoxidizing module, 63 denotes a vacuum pump, 61 denotes a bundle of hollow fiber membranes, and 62 denotes a bundle of hollow fiber membranes 61.
This is the case that accommodates. What differs from the conventional apparatus is a pipe connection in which a deoxygenating device 60 is provided in the middle of a pipe 21 for sending cooling water from the cooling device 10 to the oscillator main body 1.

The deoxygenating apparatus 60 of this embodiment includes a hollow fiber membrane type deoxidizing module 64 and a vacuum pump 63. The deoxygenation module 64 has a configuration in which a bundle of thin thread-like hollow fiber membranes is covered with a case 62.
The cooling water that has entered from one side flows through the hollow fiber membrane and reaches the other side. The case 62 is evacuated by the vacuum pump 63, and the outside of the hollow fiber membrane is in a reduced pressure state. Water molecules hardly pass through the hollow fiber membrane of the deoxygenation module 64, but have the property of passing gas (oxygen), and the cooling water flowing from the inside of the hollow fiber membrane to the outside of the depressurized hollow fiber membrane The dissolved oxygen will be released as a gas. In this way, the amount of dissolved oxygen can be reduced by passing through the deoxidizer 60. Since the laser oscillator according to the configuration of this embodiment can reduce the amount of dissolved oxygen in the cooling water of the heat exchanger 5, the rate of progress of the interface corrosion progressing at the boundary between the brazing material 5d and the copper pipe 5b due to phosphorus is increased. Can be reduced.

The corrosion prevention system in a building water supply system described in Japanese Utility Model Application Laid-Open No. 4-25860, which uses the deoxidizer 60 described in the conventional example, prevents rust itself due to oxidation of piping. As in the heat exchanger 5 of the laser oscillator, there is no oxide film in the copper tube due to the use of pure water, and there is no protection by the oxide film. The mechanism of prevention is completely different. In particular,
What is prevented by the embodiment of the present invention is corrosion of the heat exchanger 5, which is also called boundary corrosion, which occurs at seams of pipes and the like. The environment in which the heat exchanger 5 is used is also in a vacuum environment, and severe corrosion in which pinhole corrosion is not allowed.

Further, in this embodiment, by using the hollow fiber membrane type deoxidizer 60, the service life can be extended as compared with the buffer 70 and the like described in Embodiment 9 described later.
Since there is no loss of ions into the cooling water and the conductivity can be lowered, the life of the ion exchange resin can be extended. In addition, since dissolved gas other than oxygen can be removed, the purity of cooling water can be improved. This is presumed to be effective for improving the insulation of the cooling water and for corrosion other than the corrosion targeted by the present embodiment.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed facing the inside of the housing 2, and the laser medium gas circulating in the housing 2 Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates a laser beam, a deoxygenator 60 is provided in a closed circuit of cooling water for cooling the heat exchanger 5, and this can be an embodiment corresponding to the claims. . Therefore,
The amount of dissolved oxygen can be reduced by passing through the deoxygenation device 60, and the laser oscillator according to the configuration of this embodiment can reduce the amount of dissolved oxygen in the cooling water of the heat exchanger 5; The rate of progress of interface corrosion that progresses at the boundary between 5d and copper tube 5b can be reduced.

Embodiment 5 FIG. FIG. 7 is a configuration diagram showing a configuration of a laser oscillator according to a fifth embodiment of the present invention. In the figure, reference numerals 65 and 66 denote pipes provided near the cooling water inlet / outlet of the pump 14 provided in the cooling device 10 and connected to the deoxidizing device 60. The difference from the fourth embodiment is that the deoxygenating device 60 is
The point is that the cooling water is not arranged in series with the pipe 21 that sends the cooling water from 0 to the oscillator main body 1, but is arranged in parallel with the cooling system. In the configuration of the fifth embodiment, the cooling device 10 is
All of the cooling water sent to the deoxidizer 60 passes through the deoxidizer 60, that is, the deoxidizer module 64. As a result, the flow rate of water that can flow is increased, and as a result, a large-capacity deoxidizing module 64 is required, and the deoxidizing device 60 must be large. This is because it is necessary to increase the number of hollow fiber membranes and increase the cross section of the cooling water passage as the flow rate increases. In the water supply system, a deoxygenation module 64 having a capacity corresponding to the flow rate of the used tap water is required. In the case of a laser oscillator, although the flow rate of the cooling water is large, the cooling water is basically circulated. Therefore, for the flow rate of the cooling water, the deoxidizer 60 having a large capacity required in the water supply system is basically unnecessary.

In this embodiment, a circulating system for the deoxygenator 60 is provided separately from the main chilled water system circulating through the cooling device 10 and the oscillator main body 1, so that the deoxygenator 60 suitable for the required deoxygenating capacity is provided. Can be selected. The flow rate of the circulation system may be appropriately set to a flow rate required for the deoxidizer 60.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed to face the inside of the housing 2, and the laser medium gas circulating in the housing 2. Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates laser light, a deoxygenating device 60 is provided in a circulation path provided in parallel with a circulation path of cooling water for cooling the heat exchanger 5, which corresponds to the claims. An embodiment will be described. Therefore, a circulating system for the deoxidizer 60 is provided separately from the main chilled water circulating system that circulates the cooling device 10 and the oscillator main body 1, so that the deoxygenator 60 that matches the required deoxygenating capacity can be selected. The flow rate of the circulation system for the device 60 may be appropriately set to the flow rate required for the deoxygenating device 60,
There is no need to prepare a particularly large deoxidizer 60.
And the dissolution of oxygen in the cooling water can be reduced,
In the laser oscillator according to the configuration of this embodiment, the amount of dissolved oxygen in the cooling water of the heat exchanger 5 can be reduced, so that the rate of progress of corrosion can be reduced.

Embodiment 6 FIG. In the above embodiment, the circulating system for the pure water purifier and the circulating system for the deoxidizer are separately provided, but may be the same circulating system as shown in FIG. FIG. 8 is a configuration diagram showing a configuration of a laser oscillator according to a sixth embodiment of the present invention. That is, the deoxygenating device 60 is provided near the cooling water inlet / outlet of the pump 14 provided in the cooling device 10.
And a pipe 17 and a pipe 18 in which the ion exchanger 15 is connected in series. The difference from the sixth embodiment is that the deoxygenating device 6
0 and an ion exchanger 15 in a series circulation system.

As described above, also in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed to face the inside of the housing 2, and the laser medium gas circulating in the housing 2. Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates laser light, a deoxygenating device 60 is provided in a circulation path provided in parallel with a circulation path of cooling water for cooling the heat exchanger 5. Equivalent to. Therefore, a circulating system for the deoxidizer 60 is provided separately from the main chilled water circulating system that circulates the cooling device 10 and the oscillator main body 1, so that the deoxygenator 60 that matches the required deoxygenating capacity can be selected. The flow rate of the circulation system for the device 60 is
What is necessary is just to set suitably the flow rate required to 0, and it becomes unnecessary to prepare the especially large deoxygenation apparatus 60. Further, the dissolution of oxygen in the cooling water can be reduced, and the laser oscillator according to the configuration of this embodiment can reduce the amount of dissolved oxygen in the cooling water of the heat exchanger 5, so that the rate of progress of corrosion can be reduced.

Embodiment 7 FIG. In this embodiment, the granular float 100 described in the first embodiment is floated in the tank 12 of the cooling device 10 in the sixth embodiment. That is, one of the criteria for selecting the capability of the deoxidizer 60 required in the configuration of the sixth embodiment is how much oxygen in the atmosphere dissolves in the cold water system while the laser oscillator is stopped. If the amount of dissolved oxygen increases greatly while the laser oscillator is stopped, then the laser oscillator operates with a large amount of dissolved oxygen when the laser oscillator starts operating. In order to shorten the time of the state with a large amount of dissolved oxygen, it is necessary to increase the capacity of the deoxidizer 60. When the granular float 100 is floated on the tank 12 as in this embodiment, the dissolution of atmospheric oxygen into the chilled water system while the laser oscillator is stopped is suppressed,
At the time of starting the laser oscillator, a state in which the amount of dissolved oxygen is already small can be realized.

As described above, in the present embodiment, the deoxidizer 6
In a laser oscillator having zero, a granular float 100 for shutting off water and air on a water surface in the tank 12 is provided in a tank 12 provided in a cooling water circulation path for cooling the heat exchanger 5. It is. Therefore, the size of the deoxidizer 60 can be reduced. Further, in this method, the dissolution of oxygen into cold water during operation of the laser oscillator can be suppressed, so that the capacity of the deoxidizer 60 can be reduced from this aspect as well. As a result, this embodiment means that the technique of the first embodiment can be used in combination with the techniques of the second and subsequent embodiments when the present invention is implemented.
Such an embodiment is also an embodiment corresponding to the claims.

Embodiment 8 FIG. This embodiment corresponds to the tank 1 of the cooling device 10 in the sixth embodiment.
In the second embodiment, the gas containing no oxygen described in the second embodiment is blown. The details have already been described in the second embodiment, and a description thereof will be omitted. However, when used in combination with the deoxidizer 60, not only the amount of dissolved oxygen can be reduced, but also the following effects are obtained. In the configuration of the sixth embodiment, one of criteria for selecting a necessary capacity of the deoxidizer 60 is how much oxygen in the atmosphere dissolves in the chilled water system during operation of the laser oscillator.

As described above, in the present embodiment, the deoxidizer 6
In the laser oscillator having 0, an inert gas is introduced into a gas phase portion on a water surface in a tank 12 provided in a cooling water circulation path for cooling the heat exchanger 5. Therefore, by suppressing the dissolution of oxygen into the cold water during the operation of the laser oscillator, the capacity of the deoxidizer 60 can be reduced. In this embodiment, the amount of oxygen in the atmosphere dissolved into the chilled water system during the operation of the laser oscillator can be greatly reduced, so that the size of the deoxidizer 60 can be reduced. As a result, this embodiment is different from the second embodiment when the present invention is implemented.
This means that the technique of Example 1 can be used in combination with the techniques of Example 1 and the subsequent examples except for the example of Example 2. Such an embodiment is also an embodiment corresponding to the claims.

Embodiment 9 FIG. FIG. 9 is a configuration diagram showing a configuration of a laser oscillator according to a ninth embodiment of the present invention. In the figure, 70 is a buffer, 7
Reference numeral 1 denotes a partition plate for extending the passage of the cooling water. The difference from the conventional device is that a buffer 70 is provided in the middle of the pipe 21 for sending the cooling water from the cooling device 10 to the oscillator main body 1. The buffer 70 is provided with a partition plate 71 whose surface is made of a substance that is easily oxidized such as a galvanized steel sheet. The partition plate 71 is oxidized while the cooling water passes through the buffer 70 and consumes dissolved oxygen in the cooling water. I do.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed to face the inside of the housing 2, and the laser medium gas circulating in the housing 2. Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates a laser beam, the main component of the cooling water for cooling the heat exchanger 5 is a member that is more easily oxidized than a member that constitutes the heat exchanger 5 upstream of the heat exchanger 5. It passes through a buffer 70, which can be an embodiment corresponding to the claims. Therefore, in the laser oscillator according to the configuration of this embodiment, the amount of dissolved oxygen in the cooling water of the heat exchanger 5 can be reduced, so that the rate of progress of corrosion can be reduced. The structure of the buffer 70 may be any structure as long as a liquid contact area with the cooling water can be ensured, and may be a honeycomb-like structure or a structure in which a cotton-like substance to be oxidized is put in the buffer. In any case, it is preferable to secure a predetermined cooling water passage distance and increase the surface area thereof.

Although the first to ninth embodiments are based on the premise that a conventionally known heat exchanger 5 is used, the configuration of the heat exchanger 5 can be improved. Example 11 described below
In the twelfth embodiment, the configuration of the heat exchanger 5 is improved to prevent water leakage from the heat exchanger 5.

Embodiment 10 FIG. A cooling device for a laser oscillator according to a tenth embodiment of the present invention will be described. As shown in the conventional example, brazing is usually
The brazing operation is performed using a flux, but if the flux remains after brazing, it will cause corrosion of the pipe and must be completely removed. Therefore, a non-flux type brazing material that can be used without brazing at the time of brazing is used as the brazing material 5d. As the non-flux type brazing material 5d,
There is a phosphor copper brazing, and the brazing of the heat exchanger 5 of the laser oscillator has been used. However, in the case where the copper tube 5b brazed by the phosphor copper brazing is continuously used in water having a small electric conductivity, corrosion starts around the brazing portion, and the corrosion gradually begins with the brazing material 5d and the copper tube. A phenomenon progressing at the boundary of 5b was observed.

Therefore, the present inventors have used a brazing material 5d used for brazing, not a copper brazing material, but a silver brazing material containing no phosphorus. The silver brazing operation was performed in a vacuum atmosphere or a hydrogen atmosphere. Usually, in brazing using silver brazing, the use of a flux as a reducing agent is indispensable to prevent oxidation of copper. However, since copper oxidation does not occur in the vacuum atmosphere, silver brazing can be performed without a flux. In the hydrogen atmosphere, the atmosphere becomes a reducing atmosphere and copper oxidation does not occur, so that silver brazing can be performed with no flux. Compared to vacuum atmosphere, hydrogen atmosphere can be achieved under atmospheric pressure and construction is easy, and vacuum furnace (vacuum atmosphere) requires a process of opening to the atmosphere and vacuuming in a vacuum vessel, but it will be a batch process, The hydrogen furnace (hydrogen atmosphere) system can also be used for continuous construction.

As described above, in the present embodiment, the housing 2 for enclosing the laser medium gas, the discharge electrode 3 disposed to face the inside of the housing 2, and the laser medium gas circulating within the housing 2 Medium gas circulating means comprising a blower 6 for causing the laser medium gas to be cooled by a discharge generated in the discharge electrode 3, and a heat exchanger 5 for cooling the laser medium gas heated by the discharge, and cooling the heat exchanger 5 and the discharge electrode 3 with cooling water. In a laser oscillator that oscillates laser light while cooling, a cooling water circulation path for cooling the discharge electrode 3 and the heat exchanger 5 is provided, and no flux is used for brazing the copper tube 5b through which the cooling water flows. In addition, a silver solder which is not for non-flux is used. In the laser oscillator according to the configuration of this embodiment, corrosion does not start because there is no phosphorus that induces corrosion at the brazing portion of the heat exchanger.

Embodiment 11 FIG. FIG. 10 is a structural view of the heat exchanger 5 of the laser oscillator according to the first embodiment of the present invention, FIG. 11 is an enlarged sectional view of a main part of "A" part in FIG. 10, and FIG. 12 is "B" part in FIG. 13 is a side view of FIG. 10. In addition,
These show components that are conceived in FIGS.

In the drawing, reference numeral 91 denotes a tube plate for mounting the copper tube 5e, 92 denotes a casing connecting the predetermined number of copper tubes 5e and the inlet port 23 or the outlet port 24, and 93 denotes a predetermined number of copper tubes 5e and the inlet port 23. An outlet chamber 94 connects the predetermined number of copper tubes 5e and the outlet port 24. An inlet chamber 95 connects the inside of the casing 92 to the inlet chamber 93 and the outlet chamber 94.
This is a partition plate that separates the partition. The copper tube 5e has a U-shape, and has a structure in which there is no U-bend tube and there is no brazing portion in the "A" portion as in the conventional device. Also,
In the “B” portion, after the copper tube 5 e is inserted into the tube sheet 91, the copper tube 5 e is in close contact with the tube sheet 91 in a tube expanding step. Since the tubes are closely adhered so as to be able to be held in vacuum by expansion, the thickness of the tube sheet 91 must be 1.5 times or more the diameter of the copper tube 5e. Copper tube 5e
The casing 92 is welded to a tube sheet 91 in which is fixed by pipe expansion. A partition plate 95 is provided in the casing 92, and the partition 95 forms an inlet chamber 93 and an outlet chamber 94 in a space formed by the casing 92 and the tube sheet 91. The entrance chamber 93 and the exit chamber 94 are provided with an entrance port 23 and an exit port 24, respectively.

Next, the operation of the heat exchanger 5 of the laser oscillator according to this embodiment will be described. Inlet port 2 of heat exchanger 5
The cooling water entering the entrance chamber 93 from 3 enters the exit chamber 94 through the copper tube 5e and exits from the exit port 24. Therefore, in the laser oscillator according to the configuration of this embodiment, since there is no brazing portion in the heat exchanger 5 and there is no phosphorus that induces corrosion, corrosion does not start.

The joining with the copper tube 5e closely attached to the tube sheet 91 can be performed as follows. FIG. 14 shows another embodiment, and is an enlarged sectional view of a main part corresponding to the enlarged cross-sectional view of the part "B" in FIG. In the figure,
Reference numeral 96 denotes a groove provided around an insertion hole formed in the tube sheet 91. When the copper tube is expanded, the copper tube 5e in contact with the groove 96 is deformed so as to bite into the groove 96, whereby the adhesion between the tube sheet 91 and the copper tube 5e can be increased. Therefore, the heat exchanger 5 having higher reliability against leakage than the laser oscillator according to the first embodiment can be obtained.

In the above embodiment, the material of the tube sheet 91 is an important problem. It is necessary to select a material of the tube sheet 91 that does not cause electrolytic corrosion caused by electrical characteristics of the material due to joining with the copper tube 5e. In addition, a combination having high adhesion by pipe expansion is required. If copper is used as the material of the tube sheet 91, electrolytic corrosion cannot occur, but reliability of adhesion cannot be expected due to insufficient strength of the tube sheet 91. Materials satisfying both requirements are SUS304, SUS316, SUS
There is a SUS material such as 316L. With the combination of the SUS material and copper, the amount of electrolytic corrosion is extremely small, and sufficient reliability can be obtained as a joining method of the heat exchanger 5.

[0070]

As described above, in the laser oscillator according to the first aspect of the present invention, oxygen-free gas is supplied to the gaseous phase portion of the tank, so that the dissolution of oxygen into the cooling water is reduced. Suppresses the concentration of dissolved oxygen in the cooling water that promotes the progress of corrosion. Therefore, a pressure state in which the oxygen concentration of air and the like contained in the gas phase in the tank is kept low, and the amount of oxygen dissolved in the cooling water can be significantly reduced, so that the occurrence and progress of corrosion can be suppressed. Thus, the reliability of the laser oscillator can be improved.

In the laser oscillator according to the second aspect , the cooling water circuit for the heat exchanger and the cooling water circuit for the discharge electrode are separated.
Cooling of the cooling water for the discharge electrode with small electrical conductivity is performed by the heat exchanger between the cooling water for the heat exchanger,
Since pure water is not used as the cooling water for cooling the heat exchanger, the oxide adheres to the inner wall of the copper tube and forms a kind of barrier, so that the induction of corrosion is suppressed. Therefore, since the heat exchanger cooling system and the discharge electrode cooling system are provided independently, the heat exchanger cooling system is not pure water, but becomes cooling water of general quality, and the oxide adheres to the inner wall of the copper tube, The formation of a barrier prevents the induction of corrosion. Further, by adding a rust preventive agent effective against copper corrosion to the cooling water of the heat exchanger cooling system, occurrence and progress of corrosion can be suppressed, and the reliability of the laser oscillator can be improved. And the oxide on the inner wall of the copper tube
Induces corrosion as a result of the formation of a kind of barrier
Is suppressed.

In the laser oscillator according to the third aspect , a deoxygenating device provided in a cooling water system for cooling the heat exchanger cools the interface to promote the progress of interface corrosion caused by phosphorus in the heat exchanger. By suppressing the concentration of dissolved oxygen in the water, the concentration of dissolved oxygen in the cooling water, which promotes the progress of interface corrosion caused by phosphorus in the heat exchanger, is suppressed. Therefore, the amount of dissolved oxygen can be reduced by passing through the deoxygenator, the amount of dissolved oxygen in the cooling water of the heat exchanger can be reduced, and the amount of dissolved oxygen can be reduced at the boundary between the brazing material and the copper pipe caused by phosphorus. The occurrence and progress of some interface corrosion can be suppressed, and the reliability of the laser oscillator can be improved.

In the laser oscillator according to the fourth aspect, the main component is a member which is provided upstream of the heat exchanger for cooling water for cooling the heat exchanger and which is more easily oxidized than the members constituting the heat exchanger. Oxygen is consumed in the cooling water, and the concentration of dissolved oxygen in the cooling water flowing into the heat exchanger is suppressed. As described above, since the amount of dissolved oxygen in the cooling water of the heat exchanger can be reduced, the rate of progress of corrosion can be reduced, and the reliability of the laser oscillator can be increased.

In the laser oscillator according to the fifth aspect , the cooling water passing through the heat exchanger does not come into contact with the brazing portion in the circulation path of the heat exchanger, so that the cooling water passes through the heat exchanger. Since the cooling water does not contact the brazing portion in the circulation path of the heat exchanger, not only corrosion due to flux but also corrosion due to phosphorus does not occur. Therefore, the reliability of the laser oscillator can be improved.

[0075] In the laser oscillator of claim 6, wherein
In addition to the effect of the laser oscillator according to any one of claims 2 to 5 , in a tank provided in a circulation path of the cooling water for cooling the heat exchanger, a water level of the cooling water in the tank is provided. Since it supplies an inert gas that does not contain oxygen to the laser, it is possible to reduce the concentration of dissolved oxygen in the cooling water, which reduces the penetration of oxygen into the cooling water and promotes the progress of corrosion of the heat exchanger. Reliability can be improved.

In claim 6 , claims 2 to
5. The laser oscillator according to any one of 5 , wherein an inert gas containing no oxygen on a surface of the cooling water in the tank is provided in a tank provided in a cooling water circulation path for cooling the heat exchanger. Since it is supplied, the dissolution of oxygen into the cooling water is reduced, and the concentration of dissolved oxygen in the cooling water that promotes the progress of corrosion of the heat exchanger is suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a tank of a cooling device for a laser oscillator according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a tank showing another embodiment of the laser oscillator cooling device according to the first embodiment of the present invention.

FIG. 3 is a schematic view of a tank of a cooling device for a laser oscillator according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a configuration of a laser oscillator according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a configuration of a laser oscillator according to a fourth embodiment of the present invention.

FIG. 6 is an explanatory diagram of a deoxidizer used in a laser oscillator according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram showing a configuration of a laser oscillator according to a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram showing a configuration of a laser oscillator according to a sixth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a configuration of a laser oscillator according to a ninth embodiment of the present invention.

FIG. 10 is a structural view of a heat exchanger of a laser oscillator according to a first embodiment of the present invention.

FIG. 11 is an enlarged sectional view of a main part of “A” part in FIG. 10;

FIG. 12 is an enlarged sectional view of a main part of a “B” part in FIG. 10;

FIG. 13 is a side view of FIG. 10;

FIG. 14 shows a laser oscillator according to a first embodiment of the present invention, and is a main part enlarged sectional view corresponding to the main part enlarged sectional view of a "B" part in FIG.

FIG. 15 is a perspective view showing a configuration of an oscillator main body of a conventional laser oscillator.

FIG. 16 is a configuration diagram showing a configuration of a conventional laser oscillator.

FIG. 17 is a structural diagram of the heat exchanger shown in FIG.

FIG. 18 is an enlarged cross-sectional view of a main part of “A” part in the heat exchanger shown in FIG.

FIG. 19 is an enlarged cross-sectional view of a main part of a “B” part in the heat exchanger shown in FIG. 17;

20 is an enlarged sectional view of a main part of a “C” part in FIG. 19;

FIG. 21 is a schematic diagram of a tank of a conventional laser oscillator cooling device, and corresponds to the tank in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Oscillator main body, 2 housings, 3 discharge electrodes, 5 heat exchangers, 10 cooling devices, 5e copper tubes, 5d brazes, 60
Deoxygenator, 70 buffers, 100 floats.

Continuation of the front page (56) References JP-A-3-165082 (JP, A) JP-A-5-124694 (JP, A) JP-A-61-147200 (JP, A) JP-A-63-12185 (JP) JP-A-5-77032 (JP, A) JP-A-50-147410 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01S 3/00-3/30 JICST File (JOIS)

Claims (6)

(57) [Claims] 1. A housing for enclosing a laser medium gas, a discharge electrode disposed facing the inside of the housing, a medium gas circulating means for circulating the laser medium gas in the housing, and A heat exchanger that cools the laser medium gas that has become hot due to the discharge generated at the electrode; and a laser oscillator that oscillates laser light while cooling the heat exchanger and the discharge electrode with cooling water. A laser oscillator, wherein an inert gas containing no oxygen is supplied to a tank provided in a circulation path of cooling water to be cooled on a surface of the cooling water in the tank. 2. A housing for enclosing a laser medium gas, a discharge electrode disposed facing the inside of the housing, medium gas circulating means for circulating the laser medium gas in the housing, and A heat exchanger that cools the laser medium gas that has become hot due to the discharge generated at the electrode, and a laser oscillator that oscillates laser light while cooling the heat exchanger and the discharge electrode with cooling water, The circuit for cooling water and the cooling water for the discharge electrode are separated, and the cooling water for the heat exchanger is placed on the inner surface of the copper tube of the heat exchanger.
A laser oscillator , wherein water for forming a rear is used, and cooling of cooling water for a discharge electrode having low electrical conductivity is performed by a heat exchanger between the cooling water for a heat exchanger. 3. A housing for enclosing a laser medium gas, a discharge electrode disposed facing the inside of the housing, a medium gas circulating means for circulating the laser medium gas in the housing, and A heat exchanger that cools the laser medium gas that has become hot due to the discharge generated at the electrode; and a laser oscillator that oscillates laser light while cooling the heat exchanger and the discharge electrode with cooling water. A laser oscillator comprising a deoxygenator provided in a circulation path provided in parallel with a circulation path of cooling water to be cooled. 4. A housing for enclosing a laser medium gas, a discharge electrode disposed facing the inside of the housing, medium gas circulating means for circulating the laser medium gas in the housing, and A heat exchanger that cools a laser medium gas heated to a high temperature by a discharge generated at an electrode, and a laser oscillator that oscillates laser light while cooling the heat exchanger and the discharge electrode with cooling water, wherein the heat exchanger is A laser oscillator, wherein the cooling water to be cooled passes through a buffer mainly composed of a member that is more easily oxidized than a member that constitutes the heat exchanger, at an upstream portion of the heat exchanger. 5. A housing for enclosing a laser medium gas, a discharge electrode disposed to face the inside of the housing, a medium gas circulating means for circulating the laser medium gas in the housing, and A heat exchanger that cools a laser medium gas heated to a high temperature by a discharge generated at an electrode, and a laser oscillator that oscillates laser light while cooling the heat exchanger and the discharge electrode with cooling water, wherein the heat exchanger is A laser oscillator, wherein passing cooling water does not come into contact with a brazing portion in a circulation path of the heat exchanger. 6. An inert gas containing no oxygen on the surface of the cooling water in the tank is supplied into a tank provided in a cooling water circulation path for cooling the heat exchanger. The laser oscillator according to any one of claims 2 to 5 , wherein