JPS6223182A - Gas laser device - Google Patents

Abstract

PURPOSE:To minimize a pressure loss by providing a heat exchanger, in which heat conducting plates are arranged along a flow of a laser medium gas at an inlet, on the inlet side of a circulation fan. CONSTITUTION:A heat exchanger 17 is provided with heat conducting plates 17a having the same length as the auxial length of the circulation fan and arranged radially to the shaft of the circulation fan, and a water cooling pipe 17b curved into arc and connected thermally with heat conducting plates. As the heat conducting plates 17a of the heat exchanger 17 are arranged along a flow of a laser medium gas at an inlet of the circulation fan, they do not prevent the gas flow. Accordingly, the influence upon the performance of the fan can be reduced and uniform low-temperature gas flow can be generated efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas laser device, and particularly to the structure of a cooling device for a laser medium gas.

[Conventional technology]

An example of the configuration of a conventional gas laser device is shown in FIG. In the figure, reference numeral 1 denotes a closed container that isolates the laser medium gas from the atmosphere, and a propeller fan 2 circulates the laser medium gas in the container 1 through a discharge section between discharge electrodes 3 and a heat exchanger 4. The optical resonator formed by the rear mirror 5 and the output mirror 6 is
They are placed across the population inversion region of the laser medium gas excited in the discharge section 3, and the laser beam is extracted from the output mirror 6.

When configuring this type of gas laser device compactly,
The gas flow has to be bent sharply, flow separation occurs inside the bend, and the gas flow does not flow uniformly against the heat exchange surface of the heat exchanger 4, which reduces the pressure loss in the heat exchanger 4. There was a problem that this caused an increase in heat exchange performance and a decrease in heat exchange performance.

Furthermore, since the propeller fan 2 is used, expansion and contraction of the flow cannot be avoided, resulting in increased pressure loss and non-uniform gas flow distribution. Therefore, propeller fan 2 has a high output,
As the laser device becomes larger, the heat exchanger 4 must also become larger, which results in a decrease in efficiency of the laser device as a whole.

In order to solve this problem, recently, a cylindrical sealed container has been used, and the blower for circulating the laser medium gas has an impeller of approximately the same length as the longitudinal direction of the cylindrical sealed container. A system using a 7-amp through-flow has been proposed (Japanese Patent Application No. 58-27418).

[Problems to be Solved by the Invention] In the gas laser device using the above-mentioned once-through fan, the smooth flow of gas is obstructed by the heat exchanger disposed on the suction side of the once-through fan, and There was a negative impact on performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas laser device equipped with a heat exchanger that can reduce the influence on the performance of a once-through fan.

[Failure to solve the problem]

According to the present invention, in a gas laser device that uses a once-through fan to circulate laser medium gas, a heat transfer plate is provided on the suction side of the once-through fan along the flow of the laser medium gas at the suction port. Heat exchangers are installed side by side.

[Effect]

When the once-through fan is driven, a gas flow is generated on the inlet side of the fan due to the inflow of the laser medium gas. , the gas flow is not deflected by the heat exchanger plate, and pressure loss can be minimized.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, before going into the explanation of the present invention, a cross-flow fan will be briefly explained. Figure 2 shows the shape of the through-flow 7 ang and the through-flow 7
FIG. As shown in the figure, the once-through fan is constructed by arranging a multi-blade impeller 12 in a flow path composed of a front casing 10 and a rear casing 11, and the impeller 12 is rotated clockwise. By rotating it, the flow (throughflow) shown in the figure can be generated.

The direction of the flow of this 7 am flow on the suction port side is toward the rotation axis of the spindle impeller 12. Note that the streamline a indicates a stagnation streamline, and the shaded area indicates a vortex flow.

Furthermore, the cross-flow fan can generate a two-dimensional flow that is independent of the axial position of the impeller 12, and by extending the cross-flow fan in the axial direction, it is possible to generate a wide and wide flow required for the gas laser device. It is possible to generate a uniform flow in the width direction.

FIG. 1 is a sectional view showing an outline of a gas laser device in which the above-mentioned through-flow 7 am is applied as a blower for laser medium gas.

Note that the same components as those of the above-mentioned cross-flow fan are given the same numbers.

This gas laser device mainly includes an impeller 12, a cylindrical vacuum container 13, and a guide duct 14 including a front casing 10.
, a guide duct 15 including a rear casing 11, a discharge electrode 16, a heat exchanger 17, and a cooling water pipe 18.

The cylindrical vacuum vessel 13 blocks the outside air from the laser medium gas, which is a mixed gas of 1, N, and He.
A part of it serves as a guide duct for the flow of laser medium gas.

The guide ducts 14 and 15 together with the inner wall of the container 13 form a circulation path for the laser medium gas. Further, as described above, the impeller 12 is disposed within the flow path formed by the front casing 10 portion of the guide duct 14 and the rear casing 11 portion of the guide duct 15, thereby forming a cross-flow fan.

The discharge electrode 16 is disposed in the longitudinal direction of the container 13 across the discharge section 19 in the circulation path, and the heat exchanger 17 is disposed on the inlet side of the once-through fan. Further, a cooling water pipe 18 is provided in a guide duct portion that forms a circulation path from the discharge section 19 to the heat exchanger 17.

Now, the low-temperature laser medium gas sent out by the cross-flow fan passes through the discharge section 19. In the discharge section 19, the laser medium gas that is sent sequentially is continuously excited by the discharge between the discharge electrodes 16, creating a population inversion region in the discharge section, and the energy stored in this population inversion region is converted into a flow. The laser beam is extracted as a laser beam from an optical resonator (not shown) K disposed perpendicularly to the laser beam. Then, the discharge section 19
The high-temperature laser medium gas whose temperature has increased by passing through is cooled by a heat exchanger 17.

Next, the structure of the heat exchanger according to the present invention will be explained.

Figure 3 shows the once-through 7 am and heat exchanger 17 in Figure 1.
FIG. 4 is a partial perspective view of the heat exchanger 17. In this heat exchanger 17, heat exchanger plates 17a having the same length in the axial direction of the once-through fan are arranged radially with respect to the axis of the once-through fan, and water-cooled pipes 17b bent in an arc shape are connected to each heat exchanger plate. It is connected thermally.

Each heat exchanger plate 17a of the heat exchanger 17 having such a configuration has a through-flow 7
The arrangement overflows the flow of the laser medium gas (see FIG. 2) at the inlet of the tube, so the flow of the gas is not obstructed.

FIG. 5 is a partial perspective view showing another embodiment of the heat exchanger according to the present invention. Heat exchanger 1 shown in Figures 3 and 4
7 is a heat exchanger plate 17 by flowing cooling water through a water cooling pipe 17b.
This method cools the heat exchanger 2 shown in Fig. 5.
No. 0 is a type in which cooling water is allowed to flow inside the heat exchanger plate 20a.

FIG. 6 is a partial perspective view showing still another embodiment of the heat exchanger, in which the heat exchanger 21 has a fan-shaped heat transfer plate 21a having a cross-sectional shape of the inlet of a cross-flow fan, and an axis of 7 am of cross-flow. Direction V
The CGs are arranged in parallel and are formed by thermally connecting straight water-cooled pipes 21b to each heat exchanger plate.

That is, since the cross-flow fan generates a uniform flow along its axial direction, that is, a two-dimensional flow, the heat exchanger plate 21a placed perpendicular to the axial direction prevents the laser medium flowing into the cross-flow fan. Does not obstruct gas flow.

Note that the heat exchanger is not limited to the above embodiments, and for example,
A combination of the heat exchanger plates shown in FIG. 4 and FIG. 6, and a heat exchanger plate in which the shape of the heat exchanger plate is not a flat plate but a corrugated plate are conceivable. In short, any material may be used as long as it does not obstruct the flow on the suction side of the cross-flow fan.

In addition, the cooling water pipe 18 (Fig. 1) is disposed around the outer periphery of the guide duct that forms a circulation path from the discharge section 19 to the heat exchanger 17, and passes through the discharge section 19 to raise the temperature. The above-mentioned path portion heated by the high-temperature gas is cooled.

That is, the above-mentioned path portion is exposed to high-temperature gas, and its surface temperature rises to around the gas temperature. As the temperature rises, outgassing from the surface increases, which becomes impurities (particularly H and O molecules) in the laser medium gas, which becomes a factor that shortens the sealing operation time of the gas laser. Therefore, by cooling the high temperature gas path portion with the cooling water pipe 18, degassing is suppressed. - For example, since the amount of H,0 adsorbed on lead silicate glass decreases exponentially as the surface temperature decreases, cooling the high temperature gas path has a great effect on suppressing outgassing.

Furthermore, if a low-outgassing material (for example, stainless steel, special extruded aluminum alloy, etc.) is used as the material for the high-temperature gas path, outgassing can be further suppressed.

In addition, the cooling of the path portion by the cooling water pipe 18 indirectly cools the high temperature gas, and plays an auxiliary role of the heat exchanger 17. Note that the means for cooling the high-temperature gas path portion is not limited to the cooling water pipe 18, and various other means can be considered, and the applied laser device is not limited to one using a cross-flow fan.

〔Effect of the invention〕

As explained above, according to the present invention, in a gas laser device using a once-through fan, the heat exchanger is configured so as not to obstruct the flow of the laser medium gas at the inlet of the once-through fan, so that the performance of the fan is affected. It is possible to reduce the influence of gas flow, and to efficiently generate a low-temperature, uniform gas flow.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an outline of the gas laser device according to the present invention, FIG. 2 is a diagram used to explain the once-through 7 am, FIG. 3 is an enlarged view of the once-through fan and heat exchanger in FIG. 1, 4 is a partial perspective view showing the detailed structure of the heat exchanger in FIG. 1, and FIGS. 5 and 6 are partial perspective views showing other embodiments of the heat exchanger according to the present invention, respectively. FIG. 7 is a perspective view showing an outline of a conventional gas laser device. 10... Front casing, 11... Rear casing, 1
2... Impeller, 13... Cylindrical vacuum container, 14゜1
5... Guide duct, 16... Discharge electrode, 17゜2
0.21--Heat exchanger, 17a, 20a, 21a...
- Heat exchanger plate, 17b, 21b...water cooling pipe, 18...cooling water piping, 19...discharge part. Figure 1 Figure 7 Front' - Shinde Figure 2 Figure 3

Claims (5)

[Claims] (1) In a gas laser device that uses a cross-flow fan to circulate laser medium gas, a heat transfer plate is arranged on the suction side of the once-through fan along the flow of the laser medium gas at the suction port. A gas laser device characterized by being equipped with an exchanger. (2) The heat exchanger according to claim (1), wherein heat transfer plates having the same length as the axial length of the once-through fan are arranged radially with respect to the axis of the once-through fan. Gas laser equipment. (3) The heat exchanger is defined in claim (1), in which fan-shaped heat transfer plates having a cross-sectional shape of the inlet of the once-through fan are arranged in parallel along the axial direction of the once-through fan. gas laser equipment. (4) The heat exchanger plates are connected to water-cooled pipes bent into an arc shape passing through each heat exchanger plate.
3) The gas laser device according to any one of items 3). (5) The gas laser device according to any one of claims (1) to (3), wherein the heat transfer plate has a structure through which cooling water flows.