JPH0349276A - Gas cooling device of fast axial flow gas laser device - Google Patents

Abstract

PURPOSE:To restrain pulsation of laser gas caused by compression of positive displacement fan and to reduce pulsation of laser output by providing a pressure damping chamber to an output side of a heat exchanger inside a box of a cooling device. CONSTITUTION:Laser gas 5 passes through a cooling device 11B of a first step from pipings 8A, 8B, passes through a cooling device 11A of a second step from a positive displacement fan 6 and is fed to a discharge section of a gas laser oscillator. A pressure damping space 13 is formed up and down a heat exchanger 12 inside the cooling device 11A of the second step. Thereby, the laser gas 5 which is pulsated from the fan 6 and fed inside the cooling device 11A is cooled by the heat exchanger 12 and depressurized, and pulsation is thereafter damped in the wide pressure damping space 13. Therefore, laser output which is projected from an oscillator does not pulsate either, thereby realizing precision processing. Additionally, if a pressure damping is provided also to a cooling device 11B, effect can be further improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gas cooler for cooling laser gas of a high-speed axial flow gas laser device.

(Prior Art) In FIG. 4, which shows a gas circulation system diagram of a conventional high-speed axial flow gas racer device, inside the discharge tube 1, a resonator mirror 9A is installed at the right end, and a resonator mirror 9B is installed at the left end. Between these resonator mirrors 9A and 9B, in order from the right side, there are cathodes 2A, anodes 3A, 3B, cathodes 2B, 2C.
, anode 3C, 3D.

A cathode 2D is attached, and a total of four pairs of discharge electrodes form four discharge portions 4, which excites the laser gas 5 sealed inside the discharge tube 1 to generate laser light.

Further, below the discharge tube 1 in the figure, the upper end is the anode 3 of the discharge tube 1.
A cooler 7B is provided, in which the lower end of a pair of pipes 8A connected between A and 3B and between anodes 3C and 3D is connected to the inlet side,
The outlet side of this cooler 7B is connected to the inlet side of the positive displacement blower 6, and the outlet side of this positive displacement blower is connected to the inlet side of the cooler 7Δ.

Furthermore, one end of left and right piping 8B is connected to the outlet side of this cooler 7A, and the other side of these piping 8B branches into a U-shape, and is connected to the right side of the cathode 2A of the discharge tube 1 and the left side of the cathode 2B. and are connected to the right side of the cathode 2C and the left side of the cathode 2D, respectively.

In the cooler of the high-speed axial flow gas laser device configured in this manner, the laser gas 5 heated in the discharge section 4 is sent to the cooler 7A by the positive displacement fan 6 via the heat exchanger 7B, and is further cooled and then passed through the piping. For example, carbon dioxide gas is fed into the discharge tube 1 through 8B, and the gas pressure is 1001 ur.
The flow rate is 150 to 2 Hm/s.

(Problem to be solved by the invention) However, in the gas cooler of the high-speed axial flow gas laser device configured as described above, the laser gas 5 fed into the discharge section 4 is compressed by the rotation of the blades 6a of the positive displacement blower 6. The gas is compressed four times in one rotation of the two blades 6a and sent out, which causes the laser gas 5 in the discharge section 4 to also pulsate.
As a result, the laser beam 5 emitted from the oscillator also pulsates.

Then, if this laser beam 5 is used for cutting, for example, unevenness will be formed on the cut surface, impairing the characteristics of the axial flow type laser processing machine. Therefore, it is possible to reduce the pulsation by changing the capacitive blower 6 to a turbo type blower, but this is not practical due to both longevity and cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas cooler for a high-speed axial flow gas laser device that can easily reduce the pulsation of laser light due to pulsation of laser gas.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention provides a high-speed axial-flow gas laser device in which laser gas is fed to the discharge section of the high-speed axial-flow gas laser device using a positive displacement blower and a cooler on the output side thereof. In the gas cooler, by providing a pressure damping chamber at least on the output side of the heat exchanger inside the cooler box, the pulsation of the laser gas that pulsates due to the compression of the positive displacement blower is reduced, and the pulsation of the laser light is reduced. This is a gas cooler for a high-speed axial flow gas laser device.

(Example) Hereinafter, one example of the gas cooler of the gas laser device of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a gas cooler of a gas laser apparatus according to the present invention, and FIG. 2 is a partial vertical sectional view of FIG. 1.

In FIG. 1, two blades 6 are installed inside the lower end of the first stage cooler 11B, to which piping 8A, 8B for laser gas 5 sent from a laser oscillator (not shown) is connected.
A positive displacement blower 6, designated by a and 6b, is connected via a pipe 14B. On the other hand, on the right side of this positive displacement blower 6,
The lower end of the second stage cooler +1A is connected with piping +4A,
The upper part of this cooler 11A is connected to pipes 8C and 8D that are connected to a discharge section of a gas laser device (not shown).

Next, in FIG. 2 showing a vertical cross section of the second-stage cooler +1A in FIG. A heat exchanger 12 with refrigerant pipes 16 projecting laterally from above and below is housed in the heat exchanger 12, and pressure damping spaces I3 are formed above and below this heat exchanger 12. A pipe 14A is connected to the lower end of the cooler 11Δ, and the minus stage cooler 11B has a similar structure.

In the gas cooler 11A of the gas laser device having such a configuration, the laser gas 5 pulsating from the positive displacement blower 6 and sent into the cooler +1A is compressed by the positive displacement blower 6, pulsating, and being warmed. After being cooled and depressurized in a heat exchanger 12, it is sent to a wide pressure attenuation space 13 where pulsation is attenuated, and then sent to a discharge section of a gas laser oscillator (not shown).

Therefore, the laser light emitted from the oscillator (not shown) does not pulsate, and there is no unevenness on the cut surface, resulting in a gas laser device that can perform precise processing as expected using an axial laser oscillator.

Further, by providing the cooler 11B on the input side of the blower 6, not only the laser gas 5 is further cooled, but also the pulsation caused by the suction of the blower 6 is reduced, so that the effect of the cooler +1A is further improved.

Note that a pressure damping chamber 13 is provided to effectively damp pulsation.
The cross-sectional area of the flow path is determined by the following equation (1) and (2j).

F x L = 50 ~ 90 - (1) m”s
2/S+ >Io ---(2) Here, F
is the pulsation frequency (Hl), and L is the length of the pressure damping chamber 13 (m
), S+ is the cross-sectional area (m2) of the pipe 15, and S2 is the cross-sectional area (m2) of the pressure damping chamber 13.

FIG. 3 shows another embodiment of the gas cooler of the gas laser device of the present invention, and shows the case where the pipe +4A is connected from the right side of the cooler +1A. In this case, an elbow is not required when piping the roots-type blower 6, so there is an advantage that the piping work becomes easy.

[Effects of the Invention] As described above, according to the gas cooler for a high-speed axial gas laser device of the present invention, the high-speed axial gas cooler sends laser gas to the discharge section of the high-speed axial gas laser device using a positive displacement blower and a cooler on its output side. In the gas cooler of the flow-type gas laser device, a pressure attenuation space is provided at least on the output side of the heat exchanger inside the cooler box to attenuate the laser gas, so pulsations in laser output can be easily suppressed without installing additional equipment. It is possible to obtain a gas cooler for a gas laser device that can reduce the amount of energy and exhibit the characteristics of an axial laser beam.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the gas cooler of the high-speed axial flow gas laser device of the present invention, and FIG. 2 is a longitudinal cross-sectional view showing the main parts of the cooler of the high-speed axial flow gas laser device of the present invention. , 3rd
This figure shows another embodiment of the gas cooler of the high-speed axial flow type gas laser device of the present invention, and FIG. 4 is a diagram showing a gas circulation system diagram of the conventional gas laser device. 6... Positive displacement air blower 11A, IIB... Heat exchanger 13... Pressure damping chamber (8733) Agent: Patent attorney Yoshiaki Inomata (and others)
1 person)

Claims (2)

[Claims] (1) In a gas cooler for a high-speed axial-flow gas laser device, in which the laser gas in the discharge tube of the high-speed axial-flow gas laser device is circulated through a positive displacement blower connected to the discharge tube via piping and a cooler on its output side. A gas cooler for a high-speed axial flow gas laser device, characterized in that a pressure damping space is provided on the output side of the box of the gas cooler. (2) A gas cooler for a high-speed axial flow gas laser device according to claim 1, wherein pressure damping spaces are provided on the inlet and outlet sides of the box body of the gas cooler.