WO2005104309A1

WO2005104309A1 - Laser oscillator and laser processing machine

Info

Publication number: WO2005104309A1
Application number: PCT/JP2004/005706
Authority: WO
Inventors: Kazuo Sugihara; Satoshi Nishida; Miki Kurosawa
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2004-04-21
Filing date: 2004-04-21
Publication date: 2005-11-03
Also published as: JP4270277B2; TW200536220A; JPWO2005104309A1

Abstract

A laser oscillator and a laser processing machine according to the invention are such that installed downstream of an insulation plate (21) constituting a discharge electrode (1) as seen in the direction of a laser gas flow is a second cooling pipe (23) separate from a first cooling pipe (22) which is a main cooling pipe, the first and second cooling pipes (22, 23) being pressed against the insulation plate (21) by a spring (27) through a press member (29). This arrangement makes it possible to accommodate a difference in the amount of deformation resulting from a difference in temperature expansion coefficient between the cooling pipes (22, 23) and the insulation plate (21), thus making it possible to prevent stress rupture of the insulation plate (21). Further, the insulation plate (21) is simplified in shape and its cost is held down.

Description

Laser oscillator and laser processing machine

Technical field

The present invention relates to a three-axis orthogonal gas laser oscillator and a gas laser processing machine.

And a cooling structure of a discharge electrode for exciting a laser medium.

Rice field

Background art

FIG. 9 is a top sectional view showing an example of a conventional typical triaxial orthogonal laser oscillator, FIG. 10 is a side sectional view, and FIG. 11 is a transverse sectional view. FIG. 9 shows a cross section taken along the line BB, FIG. 10 shows a cross section taken along the line CC, and FIG. 11 shows a cross section taken along the line A--A. As shown in the figure, the laser medium ₂ such as CO ₂ , CO, He, N ₂ , and H ₂ , which is the laser medium in the gas laser enclosed in the housing 3 of the laser oscillator, is supplied to the blower 4 in the housing 3. Thereby, circulation is performed between two pairs of opposing discharge electrodes 1 in the housing 3 and a heat exchanger 5 for cooling the laser gas 2. The partial reflection mirror 6 and the total reflection mirrors 7, 8, and 9 are respectively arranged in the longitudinal direction of the housing 3, and constitute a resonator mirror. The mirrors that make up this resonator mirror are collectively called internal mirrors. The total reflection mirror 8 is slightly inclined downward, and the total reflection mirror 7 is slightly inclined upward, so that the resonance optical path forms a Z-shape, and the laser beam 5 is guided as shown in the figure. . The one including the partial reflection mirror 6 and the total reflection mirror 8 is referred to as first laser beam reflection means 10, and the one including the total reflection mirror 7 and the total reflection mirror 9 is referred to as second laser beam reflection means 11. Called.

In the laser oscillator housing 3, a first duct 13 for returning the laser gas 2 passing between the discharge electrodes 1 and 1 to the heat exchanger 5 is located downstream of the laser gas 2. Is provided. In order to make the laser gas 2 flow between the electrodes 1 efficiently, the second duct 16 shields the optical path of the laser beam 13 passing between the discharge electrode 1 and the housing 3 from the surroundings. It is provided in. The apertures 14 having openings are arranged in front of the respective reflecting mirrors so as to determine the shape of the beam mode and to play the role of a guide axis for laser beam amplification.

Next, the operation of the laser oscillator configured as described above will be described. First, a high voltage is applied to the discharge electrode 1 and a discharge occurs between the discharge electrodes〗. This discharge excites the laser gas 2, and the light generated by this is resonated by the resonator mirror. The laser beam 12 reflected by the total reflection mirror 9 reaches the total reflection mirror 8. Since the total reflection mirror 8 is tilted slightly downward, the laser beam 15 reaches the total reflection mirror 7 by tilting slightly downward from the optical axis. Since the total reflection mirror 7 is slightly inclined upward, the laser beam 15 reaches the partial reflection mirror 6 in parallel with the first optical axis. A part of the laser beam 15 that has reached the partial reflector 6 is output to the outside as a laser beam 12 as it is, and the rest of the laser beam 15 passes through the route opposite to the route described above, Return to reflector 9. The above process is repeated, and the laser beam 15 is amplified while reciprocating in the discharge space S sandwiched between the discharge electrodes 1 and 1, and is output from the partial reflecting mirror 6 to the outside. On the other hand, the laser gas 2 after the excitation circulates between the discharge electrodes 1 and 1 in the direction of the heat exchanger 5, is cooled here, passes through the blower 4, and is again guided between the discharge electrodes 1 and 1. FIG. 12 shows an enlarged view of the discharge electrode 第. The discharge electrode 1 is configured so as to sandwich the discharge space S between a pair of upper and lower containers 18 and 18 made of metal. The surfaces of the upper container 17 and the lower container 18 facing the discharge space S are open, and the openings are closed by the insulator plates 21, respectively. The inside of the upper container 17 and the lower container 18 whose openings are closed by the insulator plate 21 The atmosphere is an atmosphere separated from the atmosphere of the laser gas 2 which is a medium, and is connected to the outside of the housing 3 via bellows and the like, that is, the atmosphere. At approximately the center in the short direction of the surface facing the discharge space S of the insulator plate 21, the conductor electrode 20 and the dielectric 19 are provided.The insulator plate 21, the conductor electrode 20, and the dielectric 19 The layers are provided in this order. The discharge is generated by applying a high voltage to the conductor electrode 20, and therefore, the insulator 21 is insulated between the upper vessel 17 and the lower vessel 18 and the conductor electrode 20. The temperature rise of the conductor electrode 20, the dielectric 19, and the insulator plate 2 による due to the discharge is caused by the conductor electrode 2 on the surface facing the inside of the upper container 17 or lower container 18 of the insulator plate 21. It is cooled by a metal cooling pipe 22 provided at a position substantially on the rear side of the heat exchanger 0 through a heat conductive agent 26. Further, the conductor electrode 20 is connected to the cooling pipe 22 through a hole provided in the insulating plate 21, and is applied with a high pressure through the cooling pipe 22, and the upper vessel 17 and the lower vessel 1 8 is grounded.

As described above, in the conventional cooling structure of the discharge electrode 1, the conductor electrode 20 to which a high voltage is applied is cooled by the cooling tube 22. In a three-axis orthogonal laser oscillator, the direction of discharge, the direction of gas flow, and the optical path of the laser beam 15 are orthogonal to each other, and the laser gas 2, which has become hot due to the discharge, flows between the electrodes. It flows downstream in the gas flow direction. For this reason, the temperature of the discharge electrode 1 is low on the upstream side of the gas flow flowing therethrough because the laser gas 2 immediately after passing through the heat exchanger 5 flows, and high on the downstream side because the laser gas 2 flows after the discharge. A temperature distribution is formed. When the discharge current applied to the conductor electrode 20 is increased or when abnormal discharge occurs, the downstream temperature becomes even higher, and the discharge is caused by the stress generated by the temperature difference between the upstream and downstream sides. The insulator plate 21 of the electrode 1 was sometimes destroyed.

Also, for example, as shown in Japanese Patent Application Laid-Open No. 5-327071, On the downstream side of the laser gas flow of the dielectric having the structure also serving as the insulator plate 21 and the dielectric 19 of the conventional laser oscillator, a metal cooler containing a cooling medium is provided in a concave portion provided in the dielectric. In some cases, the downstream side of the electrode is cooled. However, in this case, it is necessary to process the dielectric, for example, by providing a concave portion for providing a cooler in the dielectric, so that the shape of the dielectric becomes complicated, resulting in a problem of high cost. In addition, the dielectric and the material of the cooler must have the same coefficient of linear expansion.If the two materials have different coefficients of linear expansion, when the temperature changes, the amount of thermal deformation of both materials increases, There was also a problem that the body or the cooler was destroyed by the stress generated by the difference in the amount of deformation. Disclosure of the invention

The present invention has been made to solve the above-mentioned problems, and has a discharge electrode having a structure for efficiently and simply cooling a downstream portion of a laser flow, a laser oscillator that maintains a stable discharge, and laser processing. The purpose is to get the opportunity.

In the laser oscillator and the laser beam machine according to the present invention, a second cooling member is installed on the downstream side of the discharge portion of the discharge electrode in the laser gas flow direction, and the cooling member is mounted on an insulator plate by a panel or the like. It is installed with a structure that can be held down by an elastic body, and has a structure that can absorb the difference in the amount of deformation caused by the difference in temperature between the cooling member and the insulator plate or the difference in the coefficient of linear expansion. A discharge electrode characterized by having a structure for cooling an insulator plate that is heated by the passage of the discharged gas.

The present invention has a structure in which a cooling member is provided downstream of a discharge portion of a discharge electrode in a gas flow direction, and the cooling member is pressed against a material to be cooled by an elastic body such as a panel. The insulator plate has a simple shape and the cost is reduced. Can be In addition, it is possible to prevent stress breakdown due to a difference in the amount of thermal deformation between the insulator plate and the cooling member. Brief Description of Drawings

FIG. 1 is a schematic diagram of a laser beam machine according to Embodiment 1 of the present invention. FIG. 2 is a transverse sectional view of a discharge electrode of the three-axis orthogonal laser oscillator according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a three-axis orthogonal laser oscillator according to Embodiment 1 of the present invention as viewed from above a discharge electrode.

Fig. 4 (a) shows the calculation results of the temperature distribution of the discharge electrode in the conventional method of cooling the discharge electrode of a three-axis orthogonal laser oscillator.

FIG. 4 (b) is a calculation result of the temperature distribution of the discharge electrode in the method for cooling the discharge electrode of the three-axis orthogonal laser oscillator according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view of a discharge electrode of a three-axis orthogonal laser oscillator according to Embodiment 2 of the present invention.

FIG. 6 is a transverse sectional view of a discharge electrode of a three-axis orthogonal laser oscillator according to Embodiment 3 of the present invention.

FIG. 7 is a cross-sectional view of a discharge electrode of a three-axis orthogonal laser oscillator according to Embodiment 4 of the present invention.

FIG. 8 is a transverse sectional view of a discharge electrode of a three-axis orthogonal laser oscillator according to a fifth embodiment of the present invention.

FIG. 9 is a top sectional view showing a general three-axis orthogonal laser oscillator. FIG. 10 is a side sectional view showing a general three-axis orthogonal laser oscillator.

FIG. 1 is a cross-sectional view showing a general three-axis orthogonal laser oscillator. Fig. 12 is a cross-sectional view showing a discharge electrode of a general triaxial orthogonal laser oscillator. FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

FIG. 1 is a diagram showing a laser beam machine according to Embodiment 1 for carrying out the present invention. Portions having the same configuration as the above-described conventional technology are denoted by the same reference numerals as those of the conventional technology, and description thereof is omitted. The laser beam 102 emitted from the laser oscillator 101 supplied with the high-frequency high-voltage power from the high-frequency high-voltage power supply 103 is processed by a plurality of transmission mirrors 104 to the processing head mounted on the laser processing machine main body 100. The light is guided to 105, condensed by a condenser lens 106 mounted on the processing head 105, and illuminated on the workpiece 107. The workpiece 107 is moved to a desired position or position by an assist gas such as nitrogen, oxygen, or air supplied from a processing head 105 whose position can be freely changed, and a focused laser beam 12. Processing such as cutting, welding, drilling, and surface modification is performed on the shape. In the above description, the position of the processing head 105 was made variable. However, it is desired that the processing head 105 moves in one of two directions perpendicular to each other, and that the workpiece 107 moves in the other direction. In some cases, desired processing may be performed by performing the processing described above, or by making the workpiece 107 arbitrarily movable while the processing head 105 is fixed. The laser oscillator〗 01 and the laser processing machine main body 100 are cooled by a cooling device 102, and the laser processing machine main body 100, the laser oscillator 101 and the cooling device 102 are controlled by a control device〗. Controlled by 08. Hereinafter, the structure of the laser oscillator 101 provided in the laser processing machine will be described in detail.

In the laser oscillator according to the embodiment for carrying out the present invention, the configuration other than the discharge electrode is almost the same as that of the conventional laser oscillator. Therefore, the configuration other than the discharge electrode is shown in FIG. 9, FIG. 10, FIG. 1 1 Explanation is made with reference to the figure. FIG. 2 is a diagram showing a cross section of an upper discharge electrode among discharge electrodes provided inside the laser oscillator according to the first embodiment for carrying out the present invention. FIG. 3 is a cross-sectional view of the upper discharge electrode taken along line AA in FIG. FIG. 2 is a sectional view taken along line BB of FIG. In FIG. 2, the same components as those of the conventional discharge electrode are denoted by the same reference numerals.

As shown in FIGS. 10 and 11, the discharge electrode 1 is composed of the upper discharge electrode shown in FIG. 2, the upper discharge electrode and the upper discharge electrode symmetrically arranged with respect to the discharge space S. And a lower discharge electrode of the same structure. Here, the configuration is described using the upper discharge electrode shown in FIG.

In FIG. 2, a metal container 17 made of aluminum, stainless steel or the like having openings on the upper and lower surfaces is made of a metal lid 30 with an upper opening formed by an O-ring 28a. Similarly, the lower opening is covered with an insulator plate 21 made of ceramics, glass, or the like with the O-ring 28 b interposed therebetween. The upper and lower surfaces of the insulator plate 21 are not provided with recesses as in the prior art, and have a simple flat shape. The space surrounded by the upper vessel 17, the lid 30, the insulator plate 21, and the O-ring 28 sandwiched between the members is an atmosphere separated from the atmosphere of the laser gas 2 as a laser medium. It is connected to the outside of the housing 3 through the metal bellows 25, that is, to the atmosphere. The lid 30 and the container 17 are fixed with screws not shown.However, when fixing the insulator plate 21 and the container 17 with the screws, the insulator plate 21 is locally stressed. Since the insulator plate 2〗 may be broken, the pressing member 31 with a cross section is arranged so that the periphery of the insulating plate 21 is pressed against the container 17, and the pressing member 3 1 is connected to the container 17 Is fixed with screws not shown.

A conductor electrode 20 is provided slightly upstream of the laser gas flow from the center in the short side direction of the surface facing the discharge space S side of the insulator plate 2 、, and the conductor electrode 20 is further provided. On the surface on the S side of the discharge space, a dielectric material 19 such as ceramics or glass is provided in a layer. The conductor electrode 20 may be formed by metalizing a metal on the back surface of the dielectric 19. Disposing the conductor electrode 20 slightly upstream of the laser gas flow is because the discharge space S is curved toward the downstream side of the laser gas flow due to the laser gas flow. This is to secure insulation margin on the downstream side because the insulation performance is higher. A first cooling pipe 22 made of metal is provided at a position on the surface facing the inside of the container 17 of the insulator plate 21 and substantially behind the conductive electrode 20 via a heat conductive agent 26. The conductor electrode 20, the dielectric 19, and the insulator plate 21 heated by the discharge in the discharge space S are cooled. Inside the first cooling pipe 22, a structure capable of flowing a liquid such as water or a gas such as nitrogen as a cooling medium is provided. Further, the conductor electrode 20 is connected to the cooling pipe 22 via a power supply line (not shown) through a hole (not shown) provided in the insulator plate 21, and as shown in FIG. 22 is connected to a high-frequency high-voltage power supply 103 through a power supply line 36 through a bellows 25. As a result, a high voltage is applied to the conductor electrode 20, and discharge occurs in the discharge space S. Further, the container 17 is grounded, and the container 17 and the conductor electrode 20 are insulated by the insulator plate 21.

Further, as shown in FIG. 2, a second cooling pipe 23 made of metal is provided with a thermal conductive agent 26 downstream of the laser gas flow on the surface of the insulating plate 21 facing the inside of the container 17. Is arranged. As the heat conductive agent 26, a heat conductive sheet or a paste having good heat conductivity such as a silicon compound as another heat conductive agent may be used. A structure capable of flowing a liquid such as water or a gas such as nitrogen as a cooling medium is provided inside the second cooling pipe 23 similarly to the second cooling pipe 22. The first cooling pipe 22 is applied with high pressure, while the second cooling pipe 23 is grounded and arranged in contact with the container 17. In FIG. 2, between the first cooling pipe 22 and the second cooling pipe 23 and an eave portion 32 protruding into the inside of the vessel 17 provided at the top of the vessel 17, a A resin plate-shaped pressing member 29 for pressing the first cooling pipe 22 and the second cooling pipe 23 against the insulator plate 21 is disposed. As shown in FIG. 3, a plurality of the pressing members 29 are arranged in the longitudinal direction of the container 17 at substantially equal intervals, but the number and the spacing are determined by the size of the discharge electrode. Etc. may be determined as appropriate. The holding member 29 has a first long side end face in contact with the upper surfaces of the first cooling pipe 22 and the second cooling pipe 23. The pressing member 29 and the first cooling pipe 22 are connected by screws not shown. At both ends of the second long side end face opposite to the first long side end face of the holding member 29, there are provided holes 33 which do not penetrate, and a coil spring 27 is provided in the hole 33. The spring 27 is inserted and the position of the spring 27 is fixed. The length of the spring 27 is set longer than the depth of the hole, and the hole 3 3 is set so that the head of the spring 27 protruding from the hole 3 3 is pressed by the eaves 3 2 of the container 17. The position and depth of and the length of the spring .27 are set appropriately. Although a high pressure is applied to the first cooling pipe 22, it is insulated from the container 17 and the panel 27 by a holding member 29 which is an insulator.

With such a structure, the spring 27 pressed by the eaves 32 of the container 17 presses the pressing member 29 via the bottom surface of the hole 33, and the press pressed by the spring 27 The member 29 presses the first cooling pipe 22 and the second cooling pipe 23 so as to be in close contact with the insulator plate 21 via the heat conductive agent 26, and also enables vertical positioning. . Also, since the second cooling pipe 23 and the holding member 29 are not connected, the holding member 29 has a side surface opposite to the surface of the second cooling tube 23 that is in contact with the container 17. A protruding portion 34 is provided adjacent to the second cooling pipe 23 via a gap, so that the second cooling pipe 23 can be positioned in the short direction. The gap is a coefficient of thermal expansion between the second cooling pipe 23 and the holding member 29. It is provided to absorb the difference. Further, by pressing the panel 27 with the eaves 32 of the container 17, the cooling tube can be maintained in a pressed state even when the lid 30 is removed, so that the inside of the discharge tube can be easily checked. There is. Of course, a structure in which the spring 27 is pressed by the lid 30 may be used, or a structure in which the container 17 and the lid 30 are integrated and the panel 27 is pressed by a container having an opening only on the lower surface may be used. .

Here, the holding member 29 has been described as having a plate shape. However, the holding member 29 is inserted between the panel 27 and the first and second cooling pipes 22 and 23 so that the position of the spring 27 can be fixed. Needless to say, the shape is not particularly limited to the plate shape.

In FIG. 3, the first cooling pipe 22 and the second cooling pipe 23 are connected to a cooling device 102 via an insulating tube 24 made of urethane or the like. Cooled. The first tube 24 a passes through the inside of the bellows 25 from the cooling device 102 outside the housing 3 and is connected to the end of the first cooling pipe 22. The second tube 24 b passes through the hole 37 provided in the holding member 29 and is connected to the other end of the first cooling pipe 22 and the end of the second cooling pipe 23. It is connected. The third tube 24 c passes through the hole 37 provided in the holding member 29, passes from the other end of the second cooling pipe 23 through the inside of the bellows 25, and It is led to the cooling device 102. By adopting such a configuration, compared to a case where tubes are separately provided between the first cooling pipes 22 and the second cooling pipes 23 and the cooling devices 102, one tube 24 is provided in one system. Therefore, the diameter of the bellows 25 can be reduced. Also, as shown in FIG. 3, the second tube 24 b connecting the first cooling pipe 22 and the second cooling pipe 23 is connected to the first cooling pipe 22 and the second cooling pipe 2. By connecting the opposite ends of 3 to each other, the length of the second tube 24b can be lengthened, Discharge via water can be suppressed between the first cooling pipe 22 and the second cooling pipe 23 that are grounded. By the way, the cooling water is ion-exchanged pure water, and it has been sequentially detected that the conductivity is low.

Next, the effect of installing the second cooling pipe 23 downstream of the discharge part in the regas flow direction will be described in detail. In a three-axis orthogonal laser oscillator, the direction of discharge and the direction of gas flow are orthogonal to each other, and the laser gas heated to a high temperature by the discharge flows downstream in the gas flow direction flowing between the electrodes. For this reason, the temperature distribution is formed such that the temperature of the gas flow flowing between the discharge electrodes is low on the upstream side and high on the downstream side. When the discharge current applied to the electrodes is increased or when abnormal discharge occurs, the downstream temperature becomes even higher, and a high stress is generated due to the temperature difference between the upstream and downstream sides. Therefore, by installing the second cooling pipe on the downstream side where the temperature rises, the temperature rise on the downstream side can be reduced, and as a result, the stress caused by the temperature rise can be reduced to about 1/2. It is determined from. For example, Fig. 4 (a) shows the temperature distribution caused by the temperature rise of the discharge electrode when there is no second cooling pipe, and Fig. 4 (b) shows the temperature distribution when the second cooling pipe is installed. The calculation result of the temperature distribution is shown. As can be seen from Fig. 4, when the second cooling tube was installed, the gradient of the temperature distribution of the discharge electrode was gentle and the maximum temperature was low, indicating the effect of the second cooling tube. I have.

In the laser oscillator configured as described above, the first cooling pipe 22 and the second cooling pipe 23 are pressed against the insulator plate 21 by the panel 27 via the pressing member 29 to be brought into contact. The second cooling pipe 22 and the second cooling pipe 22 are not fixed to each other by using a structure in which the second cooling pipe is provided in the insulating plate 21 with a concave portion or the like and the position of the second cooling pipe is fixed in the concave portion. The cooling pipe 23 and the insulator 21 of 2 can be freely deformed. As a result, the first cooling pipe 22 and the second cooling pipe 22 made of a metal such as aluminum or copper are formed. Due to the difference in the coefficient of linear expansion between the tube 23 and the insulating plate 21 made of ceramics or glass, stress does not occur even if the amount of deformation differs when the temperature changes, so the insulating plate 21 may break. Can be prevented. Further, the insulator plate has a simple shape, and the manufacturing cost of the insulator plate can be reduced. Further, by installing the lid 30 on the upper surface of the container〗 7, the lid 30 can be removed and the cooling pipes 22, 23 inside the container 17 can be assembled from the opening on the upper surface, so that the assemblability is improved. .

In the laser processing machine configured as described above, the second cooling pipe 23 is arranged so as to be in contact with the insulator plate 21 on the downstream side in the laser gas flow direction from the discharge space S, and the cooling pipe 22 , 23 and the insulating plate 21 are not fixed or the cooling pipes 22 and 23 are not provided in the recesses provided in the insulating plate 21 and the insulating plate 21 and the cooling pipes 22 and 23 are not provided. By making the structure freely deformable, the discharge power can be increased more than before. As a result, the discharge power can be further increased, and the output of the oscillator can be increased, which can be expected to increase the processing speed and increase the workable plate thickness. Further, even if abnormal discharge occurs, the possibility of breakage of the insulator plate is significantly reduced, so that stable processing with little downtime can be provided as a laser beam machine. Embodiment 2

In the first embodiment, both the first cooling pipes 22 and the second cooling pipes 23 are pressed against the insulator plate 21 by the pressing members 29. However, as shown in FIG. 5, the elastic members for pressing the first cooling pipe 22 and the second cooling pipe 23 are independently provided with a first pressing member 29 a and a second pressing member 29. It may be attached via b.

In this case, the thermal deformation in the height direction of the first cooling pipe 22 and the second cooling pipe 23 If the amounts are different, in Embodiment 1, there is a possibility that the holding member 29 is inclined and the first cooling pipe 22 and the second cooling pipe 23 cannot be pressed properly. In the case of mode 2, since the first cooling pipe 22 and the second cooling pipe 23 are individually pressed against the insulator plate, there is no need to consider the difference in the amount of thermal deformation in the height direction.

By the way, FIG. 5 showing the structure of the discharge electrode according to the second embodiment simplifies the description except for the difference from the first embodiment, but is basically similar to the first embodiment. It has a structure similar to that shown in FIGS. 2 and 3. In the following embodiments, simplified diagrams are used as in the present embodiment. Embodiment 3.

In the first embodiment, the first cooling pipe 22 and the second cooling pipe 23 are configured to be pressed against the insulator plate 21 by the panel 27 via the pressing member 29. As shown in FIG. 6, the first cooling pipe 22 and the second cooling pipe 23 may be directly pressed by an elastic body 38 made of an insulating material such as resin or rubber.

In this case, as in the second embodiment, the first cooling pipe 22 and the second cooling pipe 23 are individually pressed against the insulator plate, so it is necessary to consider the difference in the amount of thermal deformation in the height direction. There is no. Further, since the insulation between the first cooling pipe 22 and the container 17 is secured by the insulator elastic body 38, the spring 27 and the cooling pipes 22, 2 in Embodiment 1 are secured. Since the holding member 29 between 3 is unnecessary, the number of parts can be reduced, and there are advantages such as compactness, low cost, and improved assemblability. Embodiment 4.

In Embodiment 1, the holding member 29 and the first cooling pipe 22 are screwed. However, as shown in FIG. 7, the holding member 29 is provided with a notch 35 for regulating the position of the first cooling pipe 22 in the short direction, and the The bond may be deleted. Further, it is desirable to provide a gap between the cutout 35 and the side surface of the first cooling pipe 22 such that the thermal expansion of the first cooling pipe 22 can be absorbed.

In this case, there is no need to provide a special structure for screwing to the first cooling pipe 22 and, of course, there is no need for screws, so that there are advantages such as low cost and improved assemblability. Embodiment 5

FIG. 8 is a transverse sectional view of a discharge electrode according to a fifth embodiment for carrying out the present invention. In FIG. 8, the structure of the discharge electrode is the same as that of the first embodiment, except that a temperature sensor 40 is provided so as to be in contact with the portion of the insulator plate 21 downstream of the laser gas flow in the container 17. The temperature sensor 40 and the control device 108 are connected by a signal line passing through a bellows 25. With the above configuration, the control device 108 can monitor the temperature of the insulator plate 21 downstream of the laser gas flow by the temperature sensor 40, and can control the laser oscillator based on the temperature.

If an abnormal discharge occurs, the temperature of the insulator plate 21 downstream of the laser gas flow rises above a specified value, so the control device 108 connected to the temperature sensor 40 detects the abnormality and discharges the oscillator. By controlling the current to stop, it is possible to avoid damage to the discharge electrode due to the occurrence of abnormal discharge. In addition, since the second cooling pipe 23 is provided, if abnormal discharge occurs, the rate of temperature rise downstream of the laser gas flow of the insulator plate 2 が is not provided with the second cooling pipe 23. Even if an inexpensive sensor with a bimetallic time constant of several seconds is used for the temperature sensor 40, It can be detected before the temperature of the body plate 21 rises to the point at which it is destroyed. As a result, downtime of the laser beam machine can be reduced or eliminated. Industrial applicability

As described above, the laser oscillator and the laser processing machine according to the present invention are particularly suitable for being used for high-power laser processing.

Claims

The scope of the claims

1-a laser oscillator which causes a laser gas to flow between a pair of discharge electrodes, applies a high voltage between the discharge electrodes to generate a discharge between the discharge electrodes, and excites the laser gas to perform laser oscillation;

A first cooling pipe provided substantially at the center of a pair of insulator plates constituting the discharge electrode,

A second cooling pipe provided downstream of the insulator plate in a direction in which the laser gas flows;

A laser oscillator comprising: an elastic body that presses the first cooling pipe and the second cooling pipe against the insulator plate.

2. The pair of insulator plates are provided with a conductor electrode on a first surface, and arranged so as to face the first surface;

The first cooling pipe is provided on a second surface on the back side of the first surface of the insulator plate,

The laser oscillator, wherein the second cooling pipe is provided on a downstream side of the second surface of the insulator plate in a direction in which the laser gas flows.

3. The elastic body is

3. The laser oscillator according to claim 1, wherein the laser oscillator directly presses the first cooling pipe and the second cooling pipe.

4. The elastic body is

3. The laser oscillator according to claim 1, wherein the first cooling pipe and the second cooling pipe are individually pressed.

5. The elastic body is

The laser according to claim 1, wherein the laser beam presses the first cooling pipe and the second cooling pipe via a pressing member. 4. Oscillator.

6. The holding member is

6. The laser oscillator according to claim 5, wherein the laser oscillator simultaneously presses the first cooling pipe and the second cooling pipe.

7. The holding member is

A first pressing member that presses the first cooling pipe,

6. The laser oscillator according to claim 5, comprising a second pressing member for pressing the second cooling pipe.

8. The holding member is

6. The laser oscillator according to claim 5, further comprising a position regulating means for regulating a position of said first cooling pipe and / or said second cooling pipe.

9. The position restricting means is:

9. The laser oscillator according to claim 8, wherein the laser oscillator is a cutout provided on the holding member.

10. The position restricting means,

9. The laser oscillator according to claim 8, wherein the laser oscillator is a projection provided on the holding member.

11. A temperature sensor provided downstream of the insulator plate in the flow direction of the laser gas;

A control device for receiving a signal from the temperature sensor and controlling an oscillator so as to stop laser oscillation when the temperature rises above a set temperature, wherein the control device comprises: Laser oscillator.

1 2 .—Laser gas flows between a pair of discharge electrodes, a high voltage is applied to the discharge electrodes to generate a discharge between the discharge electrodes, and the laser gas is output from a laser oscillator that excites the laser gas and performs laser oscillation. Laser beam In laser processing machines that perform one-piece processing,

A laser processing machine comprising the laser oscillator according to claim 1 or 2.