JP3614450B2 - Laser resonator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a laser resonator that generates laser light by exciting laser gas in a discharge tube.
[0002]
[Prior art]
Gas laser devices such as carbon dioxide lasers have high efficiency and high output, and have good beam characteristics, so they can be combined with numerical control devices to process complex shapes at high speed and are widely used. .
[0003]
FIG. 4 is a diagram showing an overall configuration of a conventional gas laser apparatus. In the figure, the gas laser device is, for example, a carbon dioxide laser, and includes a resonator 100, a gas circulation system 200, and a laser processing machine 300.
[0004]
The resonator 100 includes two discharge tubes 210 and 220 arranged in series, and the discharge tubes 210 and 220 are connected by a discharge tube holder 610. One end side of the discharge tube 210 is fixed to the end plate 410 via the discharge tube holder 310, and the other end side of the discharge tube 220 is fixed to the end plate 420 via the discharge tube holder 320. In parallel rods 710 and 720 are provided in parallel with the discharge tubes 210 and 220, and both ends thereof are fixed to the end plates 410 and 420 in the same manner as the discharge tubes 210 and 220. The invar rods 710 and 720 are made of a material having a small coefficient of thermal expansion. Thus, the resonator 100 is configured in a box shape by the invar rods 710 and 720 and the end plates 410 and 420.
[0005]
Further, a frame (pipe) 91 is provided in parallel with the discharge tubes 210 and 220, one end of which is fixed to the end plate 410, and the other end is supported by the end plate 420 via a linear bearing 421. The discharge tube holder 610 is fixed to the frame 91 via a clamp 620, and holds the discharge tubes 210 and 220 more stably. As will be described later, since the discharge tube holder 610 is positioned on the laser gas outlet side, the discharge tube holder 610 is heated by the laser gas at a high temperature, and the heat is transmitted to the frame 91, so that the frame 91 is thermally deformed. The linear bearing 421 is provided to absorb this thermal deformation.
[0006]
In this case, it is conceivable to fix the discharge tube holder 610 to the invar rod 710 or 720 side. However, when the discharge tube holder 610 is fixed to the invar rod 710 or 720 side, the invert rod 710 or 720 side is moved by its own weight. It will bend. Further, since the invar rods 710 and 720 are fixed to the end plates 410 and 420, deformation due to heat from the discharge tube holder 610 cannot be absorbed even if the coefficient of thermal expansion is low. For this reason, fixing the discharge tube holder 610 to the invar rod 710 or 720 is not performed.
[0007]
A gas pipe 205 of the gas circulation system 200 is provided so as to extend from the discharge tube holder 610, and a heat exchanger 201, a blower 202, and a heat exchanger 203 are arranged in this gas pipe 205 in this order. The laser gas heated by the discharge tubes 210 and 220 flows as indicated by an arrow A in the figure.
[0008]
That is, after being cooled through the heat converter 201 via the gas pipe 205, the gas is discharged from the blower 202, and further, the heat of the compression is removed by the heat exchanger 202 so that the temperature is always maintained at a constant temperature. Thereafter, the gas enters the discharge tubes 210 and 220 from the discharge tube holders 310 and 320 via the gas pipe 204, respectively. The laser gas introduced into the discharge tubes 210 and 220 is heated by high frequency discharge by the laser power supplies 11 and 12, and then enters the heat exchanger 201 from the discharge tube holder 610 via the gas pipe 205 and is cooled again. .
[0009]
The discharge tubes 210 and 220 have a total reflection mirror 510 and an output mirror 520 at both ends thereof to constitute a Fabry bellows type resonator, and amplify the laser light generated by the discharge and output a part thereof to the outside. The outputted laser light is changed in direction by the vendor mirror 13 and enters the laser processing machine 300 to process the workpiece. The resonator 100, the gas circulation system 200, and the laser processing machine 300 are all controlled by the numerical controller 10 according to a program stored in the memory.
[0010]
[Problems to be solved by the invention]
As described above, since the invar rods 710 and 720 are formed of a material having a low coefficient of thermal expansion, the position of the end plates 410 and 420 to which the invar rods 710 and 720 are fixed does not change. Although the frame 91 is thermally deformed, the thermal deformation is absorbed by the linear bearing 421, so that the position change on the end plates 410 and 420 side does not occur. However, since the clamp 620 of the discharge tube holder is fixed to the frame 91, the position of the clamp 620 is affected by the thermal deformation of the frame 91 and changes. For example, when the frame 91 is thermally expanded in the longitudinal direction, the position of the clamp 620 is changed under the influence, and as a result, the position of the discharge tube holder 610 is also changed.
[0011]
When the position of the discharge tube holder 610 changes, the change in position causes the alignment of the total reflection mirror 510 and the output mirror 520 to deteriorate, and as a result, the output beam power decreases and the beam mode deteriorates.
[0012]
The present invention has been made in view of these points, and an object of the present invention is to provide a laser resonator capable of always maintaining good alignment of the resonator.
[0013]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, in a laser resonator that generates laser light by exciting a laser gas in a discharge tube, end plates that are provided at both ends of the discharge tube and support the discharge tube, and the discharge tube A rod made of a material having a small coefficient of thermal expansion, supported at both ends by the end plate, and a discharge tube holder made of aluminum that is fixed to the rod and supports the discharge tube and is forcedly cooled. A laser resonator is provided.
[0014]
[Action]
End plates are provided at both ends of the discharge tube to support the discharge tube. A rod made of a material having a low coefficient of thermal expansion is provided in parallel with the discharge tube, and both ends of the rod are supported by end plates. A discharge tube holder made of aluminum for holding the discharge tube is fixed to the rod and is forcibly cooled.
[0015]
Since the discharge tube holder is forcibly cooled, heat is not transferred from the discharge tube holder to the rod even if the discharge tube holder is fixed to the rod. The rod is made of a material having a small coefficient of thermal expansion. Therefore, thermal deformation of the rod hardly occurs, and the alignment can be maintained well.
[0016]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a laser resonator according to the present invention. In the figure, the resonator 1 has two discharge tubes 21 and 22 arranged in series, and the discharge tubes 21 and 22 are connected by a discharge tube holder 61. One end side of the discharge tube 21 is fixed to the end plate 41 via the discharge tube holder 31, and the other end side of the discharge tube 22 is fixed to the end plate 42 via the discharge tube holder 32. Further, invar rods 71 and 72 are provided in parallel with the discharge tubes 21 and 22, and both ends thereof are fixed to the end plates 41 and 42, similarly to the discharge tubes 21 and 22. The invar rods 71 and 72 are made of a material having a small coefficient of thermal expansion. Thus, the resonator 1 is configured in a box shape by the invar rods 71 and 72 and the end plates 41 and 42.
[0017]
The discharge tube holder 61 is fixed to the invar rod 71 via a holder clamp 62 that is formed integrally with the discharge tube holder 61. The holder clamp 62 is provided with a cooling water channel not shown here, and the cooling water is forcedly cooled by circulating through the cooling water channel. The invar rods 71 and 72 are connected to each other by two rod clamps 81 and 82 provided on both sides of the discharge tube holder 61. Due to the rod clamps 81 and 82, the force from the discharge tube holder 61 and the holder clamp 62 applied to the invar rod 71 is also distributed to the invar rod 72. As a result, the support force of the invar rods 71 and 72 is strengthened.
[0018]
The discharge tube holder 61 and the holder clamp 62 are made of, for example, aluminum in order to reduce the weight as much as possible in order to minimize the force applied to the invar rod 71.
[0019]
Each of the discharge tubes 21 and 22 has a total reflection mirror 51 and an output mirror 52 at both ends thereof to constitute a Fabry bellows type resonator, and amplifies the laser beam generated by the discharge and outputs a part thereof to the outside.
[0020]
In this manner, the discharge tube holder 61 is fixed to the invar rod 71 via the forcibly cooled holder clamp 62. Moreover, the invar rods 71 and 72 are made of a material having a low coefficient of thermal expansion. Therefore, the thermal deformation of the invar rods 71 and 72 hardly occurs, and the alignment can be always kept good.
[0021]
Further, since the invar rods 71 and 72 are connected by the rod clamps 81 and 82, the force applied to the invar rod 71 is dispersed, and the invar rods 71 and 72 reinforce each other and strengthen their supporting force. Moreover, since the discharge tube holder 61 and the holder clamp 62 are lightened, the invar rods 71 and 72 are hardly bent.
[0022]
Further, since the frame that has been conventionally required is not required, the configuration of the resonator 1 is simplified, and the alignment work itself can be easily performed.
FIG. 2 is a diagram showing a second embodiment of the present invention. The difference from the first embodiment is that the resonator 1a is composed of four discharge tubes 21a, 22a, 23a and 24a, and three discharge tube holders 61a, 62a and 63a are provided in accordance with the discharge tubes 21a, 22a, 23a and 63a. The pipe holders 61a, 62a and 63a are fixed to the invar rod 71a. The discharge tube holder 61a connects between the discharge tubes 22a and 23a, the discharge tube holder 62a connects between the discharge tubes 21a and 22a, and the discharge tube holder 63a connects between the discharge tubes 23a and 24a. The discharge tube holders 61a, 62a and 63a are fixed to the invar rod 71a through holder clamps 64a, 65a and 66a. The two invar rods 71a and 72a are provided on one side of the discharge tube holder 63a, the rod clamp 83a provided on one side of the discharge tube holder 62a, the rod clamps 81a and 82a provided on both sides of the discharge tube holder 61a, and the discharge tube holder 63a. The rod clamps 84a are connected to each other.
[0023]
As described above, even when the resonator 1a is constituted by four discharge tubes 21a in series, etc., by fixing the three discharge tube holders 62a and the like to the invar rod 71a, the entire resonator 1a is aligned due to the influence of heat. It can be prevented from deteriorating, and the alignment can always be kept good.
[0024]
FIG. 3 is a diagram showing a third embodiment of the present invention. The difference from the first embodiment is that the discharge tubes 21b and 23b connected in series and the discharge tubes 22b and 24b connected in series are configured in parallel with each other, and a discharge tube holder 61b is provided in accordance therewith. The tube holder 61b is fixed to the invar rod 71b. The discharge tube holder 61b is provided at a connection portion between the discharge tubes 21b and 23b connected in series and a connection portion between the discharge tubes 22b and 24b connected in series. The discharge tube holder 61b is fixed to the invar rod 71b through a holder clamp 62b. The two invar rods 71b and 72b are connected to each other by rod clamps 81b and 82b provided on both sides of the discharge tube holder 61b.
[0025]
Thus, even when the resonator 1a is configured by arranging two discharge tubes 21b in series in parallel, the resonator 1b as a whole is affected by heat by fixing the common discharge tube holder 61b to the invar rod 71b. Therefore, it is possible to prevent the alignment from deteriorating and to keep the alignment always good.
[0026]
In the above description, the holder clamp is forcibly cooled. However, the discharge tube holder on the main body side may be forcibly cooled.
[0027]
【The invention's effect】
As described above, in the present invention, the forcibly cooled discharge tube holder is fixed to a rod formed of a material having a low coefficient of thermal expansion. Therefore, thermal deformation of the rod hardly occurs, and the alignment can be always kept good.
[0028]
Also, since the two rods are connected to each other, the force applied to the rods is dispersed, and the rods can reinforce each other and strengthen their supporting force.
Further, since the frame that has been necessary in the past is not necessary, the configuration of the resonator is simplified, and the alignment work itself can be easily performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a laser resonator according to the present invention.
FIG. 2 is a diagram showing a second embodiment of the present invention.
FIG. 3 is a diagram showing a third embodiment of the present invention.
FIG. 4 is a diagram showing an overall configuration of a conventional gas laser device.
[Explanation of symbols]
1, 1a, 1b Resonator 21, 21a, 21b, 22, 22a, 22b, 23a, 23b, 24a, 24b Discharge tube 61, 61a, 61b, 62a, 63a Discharge tube holder 62, 62b, 64a, 65a, 66a Holder Clamp 81, 81a, 81b, 82, 82a, 82b, 83a, 84a Rod clamp

Claims (4)

In the laser resonator that generates laser light by exciting the laser gas in the discharge tube,
End plates provided at both ends of the discharge tube to support the discharge tube;
A rod which is provided in parallel with the discharge tube and is supported at both ends by the end plate and made of a material having a low coefficient of thermal expansion;
A discharge tube holder made of aluminum fixed to the rod and supporting the discharge tube and forcibly cooled;
A laser resonator comprising: 2. The laser resonator according to claim 1, wherein when there are a plurality of the rods, the plurality of rods are connected to each other at a portion other than the end plate. 2. The laser resonator according to claim 1, wherein the discharge tube holder includes an integrated clamp portion and a main body portion, and is fixed to the rod via the clamp. 4. The laser resonator according to claim 3, wherein the discharge tube holder is forcibly cooled in the clamp portion and / or the main body portion.

Images