JP2014007352A - Gas laser oscillator - Google Patents

Abstract

An axial flow type gas laser oscillation apparatus is provided with an orifice for hindering the flow of laser gas to increase the laser gas flow velocity in the discharge tube, to make the laser gas flow uniform and to stabilize the discharge, and to increase the laser output. It was a hindrance.
In an axial flow type gas laser oscillation apparatus having an orifice of a gas restrictor in order to increase a gas flow rate and to make a laser gas flow uniform, a gas flow bypassing the upstream and downstream sides of the gas flow of the orifice A passage is provided, and the cross-sectional area of the bypass gas flow path is set to be equal to or larger than the cross-sectional area of the discharge tube by adding the cross-sectional area and the total area of the plurality of orifice holes.
[Selection] Figure 1

Description

  The present invention relates to a kW class axial flow type gas laser oscillation apparatus and gas laser processing machine mainly used for sheet metal cutting.

  A conventional axial gas laser oscillation apparatus 900 will be described with reference to FIG.

  In this figure, reference numeral 901 denotes a discharge tube made of a dielectric such as glass, and reference numerals 902 and 903 denote electrodes provided around the discharge tube. Reference numeral 906 denotes a power source connected to the electrode.

  Reference numeral 907 denotes a discharge space in the discharge tube 901 sandwiched between the electrodes 902 and 903. Reference numeral 908 denotes a total reflection mirror, and reference numeral 909 denotes a partial reflection mirror. The total reflection mirror 908 and the partial reflection mirror 909 are fixedly disposed at both ends of the discharge space 907 to form an optical resonator. Reference numeral 910 denotes a laser beam output from the partial reflection mirror 909.

  An arrow 911 indicates a laser gas flow and circulates in the gas laser oscillation device. 912 is a laser gas flow path, 913 and 914 are heat exchangers for lowering the temperature of the laser gas whose temperature has risen due to the discharge in the discharge space 907 and the operation of the blower, and 915 is a blowing means for circulating the laser gas. A gas flow of about 100 m / sec is obtained in the discharge space 907 by the blowing means 915.

  The laser gas flow path 912 and the discharge tube 901 are connected by a gas introduction part 905, and an orifice 904 of a laser gas restrictor is installed in the vicinity of the gas introduction part.

  In order to stabilize the discharge, the hole diameter of the orifice of this throttle body is set to be smaller than the cross-sectional area of the discharge tube 901, and the laser gas flow rate is reduced when the laser gas passes through the orifice. (For example, refer to Patent Document 1).

JP 2001-111139 A

  The conventional gas laser oscillation apparatus having such an orifice of the throttle body has the following problems.

  The orifice can increase the gas flow velocity in the laser discharge tube and make the gas flow uniform, but the total area of the holes in the orifice is set smaller than the cross-sectional area of the laser discharge tube. When the gas flowing through the flow path passes through the orifice and flows into the laser discharge tube, the gas flow rate is reduced, which hinders increase in laser output.

  In order to solve the above-described problems, the present invention provides a discharge tube for flowing a laser gas therein and exciting the laser gas, a laser gas introduction unit connected to the discharge tube and introducing the laser gas into the discharge tube, and the laser gas introduction unit A laser gas flow path for supplying a laser gas to and an orifice arranged between the discharge tube and the laser gas introduction section or in the vicinity of a connection portion between the discharge tube of the laser gas introduction section, A bypass gas flow path for introducing gas is provided, and the total cross-sectional area of the bypass and the total area of the orifice holes is equal to or greater than the cross-sectional area of the laser discharge tube. It is.

  The present invention makes it possible to efficiently introduce gas into the laser discharge tube without increasing the gas flow rate while having an orifice for increasing the gas flow rate in the laser discharge tube and making the gas flow uniform. Thus, a significant increase in laser output can be realized as compared with the conventional example.

Configuration diagram of gas laser oscillation apparatus according to the present invention Detailed view of the gas introduction part to the discharge tube according to the present invention Arrangement diagram showing an example of arrangement of orifice and pin electrode Detailed view of the gas introduction part to the discharge tube according to the present invention Detailed view of the gas introduction part to the discharge tube according to the present invention Configuration diagram of a gas laser processing machine using the gas laser oscillator of the present invention Configuration diagram of a gas laser oscillator according to the prior art

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated, referring drawings.

(Embodiment)
FIG. 1 shows an example of a schematic configuration of an axial flow type gas laser oscillation apparatus of the present invention.

  The axial flow type gas laser oscillation apparatus 100 includes a discharge tube 101, a pin-shaped anode 102 and a ring-shaped cathode 103, a power source 106, a total reflection mirror 108, a partial reflection mirror 109, a laser gas flow path 112, an orifice 104 of a laser gas throttle body, A gas introduction part 105 that connects the laser gas passage 112 and the discharge tube 101, a bypass gas passage 113 that can introduce gas into the discharge tube 101 without going through the orifice 104, a gas introduction part 114 that connects the bypass gas passage 113 and the discharge tube, The heat exchangers 115 and 116 and the air blowing means 117 are provided as the configuration.

  The discharge tube 101 is made of a dielectric material such as glass. A pin-shaped anode 102 and a ring-shaped cathode 103 are provided around the discharge tube 101, and a power source 106 is connected to each of the electrodes 102 and 103. The orifice 104 is installed in the vicinity of the pin-shaped anode 102. A discharge space 107 is formed in the discharge tube 101 sandwiched between the anode 102 and the cathode 103. The total reflection mirror 108 and the partial reflection mirror 109 are fixedly disposed at both ends of the discharge space 107 to form an optical resonator. An arrow 110 symbolically represents the laser beam output from the partial reflection mirror 109.

  An arrow 111 indicates a laser gas flow, and circulates through the laser gas flow path 112 and the bypass gas flow path 113 in the axial flow type gas laser oscillation device. The heat exchanger 115 and the heat exchanger 116 lower the temperature of the laser gas whose temperature has risen due to the discharge in the discharge space 107 and the operation of the blower. The air blowing means 116 is for circulating laser gas, and a gas flow of about 100 m / sec is obtained in the discharge space 107 by the air blowing means 117.

  The above is the configuration of the gas laser oscillator 100 of the present invention. Next, the operation will be described.

  The laser gas sent out from the blower 117 passes through the laser gas passage 112 and the bypass gas passage 113 and is introduced into the discharge tube 101 from the laser gas introduction portions 105 and 114. In this state, discharge is generated in the discharge space 107 from the electrodes 102 and 103 connected to the power source 104.

  The laser gas in the discharge space 107 is excited by obtaining this discharge energy, and the excited laser gas is brought into a resonance state by an optical resonator formed by the total reflection mirror 108 and the partial reflection mirror 109. A beam 110 is output. This laser beam 108 is used for applications such as laser processing.

  Due to the configuration of the axial flow type gas laser oscillation device, the gas introduction portions 105 and 114 are arranged substantially at right angles to the discharge tube 101, and the laser gas flow path 112 is a portion where the laser gas flows parallel to the gas flow in the discharge tube 101. Is generally provided. FIG. 2 shows an example of the configuration in the vicinity of the gas introduction part in detail.

  In this figure, 112a is a laser gas flow path substantially perpendicular to the discharge tube 101, 112b is a laser gas flow path parallel to the gas flow in the discharge tube 101, and 113a is larger than the orifice 104 of the bypass gas flow path 113. A gas inlet 118 on the downstream side indicates a baffle plate provided near the outlet of the bypass gas passage.

  The orifice 104 shown in FIG. 2 is formed of an insulator such as a resin-based plastic, and includes a portion that obstructs the flow of the laser gas and a plurality of holes through which the laser gas passes. The total area of the plurality of holes is a laser discharge tube. It is set smaller than the cross-sectional area.

  Further, the tip of the pin-like anode 102 in the vicinity of the gas downstream side of the orifice 104 is arranged on the same axis as the orifice or somewhat downstream, and coaxially with the center of one of the plurality of holes as shown in FIG. .

  Further, the pin-like anode 102 and the orifice 104 arranged in this way are arranged on the same side or a little downstream of the gas introduction part 105 and do not protrude into the discharge tube. Therefore, the laser beam is not damaged.

  A large amount of plasma is generated from the pin-like anode, and a fire column-like plasma flow 119 is created immediately above the pin. A glow discharge is formed in the discharge space 107 starting from the plasma flow 119 on the fire column. The glow discharge generated in the discharge tube 101 increases the gas flow velocity in the vicinity of the fire column-like plasma flow by the throttling effect by making the hole diameter of the orifice smaller than the cross-sectional area of the laser tube, and also forms a plurality of holes in the orifice. Due to the effect, the gas flow in the discharge tube 101 can be made uniform so as to be stabilized.

  Further, it is convenient to use a flexible fluororesin hose or the like for the bypass gas passage 113, and the bypass gas passage 113 is installed so as to bypass the upstream and downstream sides of the gas flow of the orifice 104. The cross-sectional area of the bypass channel 113 is set so that the sum of the cross-sectional area and the total area of the plurality of holes in the orifice 104 is equal to or larger than the cross-sectional area of the discharge tube.

  By having the bypass gas flow path 113 set in this way, the laser gas passes through the orifice 104 and compensates for the reduced gas flow rate when flowing into the discharge tube, thereby increasing the total gas flow rate flowing into the discharge tube. It becomes possible to make it.

  Further, a baffle plate 118 is provided in the vicinity of the laser gas outlet of the bypass gas passage 113 so as to be the same as or downstream of the gas introduction part 114 so as not to be damaged by the laser beam. By this baffle plate, the gas passing through the bypass gas passage 113 is smoothly flowed into the discharge tube, thereby increasing the gas flow rate without disturbing the uniform gas flow created in the discharge tube by the gas passing through the orifice 104. I can do it.

  Incidentally, the inlet 113a on the downstream side of the orifice of the bypass gas channel is an inlet 113b installed in the gas channel in which gas flows parallel to the discharge tube as shown in FIG. 4, or as shown in FIG. The same effect can be obtained at the inlet 113c provided in the heat exchanger 116.

  Since the conventional axial flow type laser gas oscillation device does not have a bypass gas flow path, when the gas flows through the orifice and flows into the discharge tube, the gas flow rate is reduced, and the amount of electric injection into the gas due to the discharge does not increase, There was a problem that the laser output was limited.

  In the present invention, while having an orifice for stabilizing the discharge, a bypass gas flow path for supplementing the gas flow rate reduced by the orifice is provided, so that the gas can flow to the discharge tube without reducing the gas flow rate. It is possible to increase the laser output, and it can be said that the structure is very excellent when used for an axial flow type gas laser oscillation device.

  Next, FIG. 7 is a block diagram of the gas laser processing machine in the embodiment of the present invention. The laser beam 110 output from the gas laser oscillation apparatus 100 of the present invention is guided to the condensing lens 122 provided in the torch 121 by the reflecting mirror 120, and the laser beam 110 condensed by the condensing lens 121 is processed as a workpiece 123. Is used for applications such as cutting and welding.

  The processed workpiece 123 is mounted on a table 124, and the processed workpiece 123 is processed into an arbitrary shape by moving the condenser lens 122 by the X-axis motor 125 and the Y-axis motor 126. In FIG. 7, the condensing lens 122 is moved by the powers 125 and 126, but the same effect can be obtained by connecting the X-axis motor 125 and the Y-axis motor 126 to the table 124 side and moving them. .

  The gas laser oscillation device and the gas laser processing machine according to the present invention include an orifice for stabilizing the discharge, and can prevent the gas flow rate from being reduced, and can increase the laser output. Useful as a processing machine.

DESCRIPTION OF SYMBOLS 101 Discharge tube 102 Pin-shaped anode 103 Ring-shaped cathode 104 Orifice 105 Gas introduction part 106 Power supply 107 Discharge space 108 Total reflection mirror 109 Partial reflection mirror 110 Laser beam 111 Laser gas flow direction 112 Laser gas flow path 112a A substantially right angle to the discharge tube Laser gas flow path 112b Laser gas flow path substantially parallel to the discharge tube 113 Bypass laser gas flow path 113a Bypass laser gas flow path inlet 113b Bypass laser gas flow path inlet 113c Bypass laser gas flow path inlet 114 Gas introduction part 115 Heat exchanger 116 Heat Exchanger 117 Blower 118 Baffle plate 119 Fire column-shaped plasma flow 120 Reflecting mirror 121 Torch 122 Condensing lens 123 Work 124 Processing table 125 X-axis motor 125 Y-axis motor 901 Discharge tube 902 Electrode 903 Electrode 904 Orifice 905 Gas introduction part 906 Power supply 907 Discharge space 908 Total reflection mirror 909 Partial reflection mirror 910 Laser beam 911 Laser gas flow direction 912 Laser gas flow path 913 Heat exchanger 914 Heat exchanger 915 Blower

Claims (5)

A gas laser oscillation device in which a discharge tube for exciting a laser gas and a flow path for circulating the laser gas while flowing the laser gas inside the discharge tube are formed,
Providing a first gas flow path and a second gas flow path for sending gas to the discharge tube;
The introduction portion of the first gas flow path to the discharge tube is provided with an orifice in which one or a plurality of holes are formed, and a pin-shaped electrode disposed in one of the holes in the orifice,
The gas laser arranged such that the introduction portion of the second gas flow path to the discharge tube is positioned behind the introduction portion of the first gas flow passage with reference to the flow direction of the laser gas in the discharge tube. Oscillator. 2. The gas laser oscillation apparatus according to claim 1, wherein a total area of a hole formed in the orifice and a total area of an introduction portion of the second gas passage to the discharge tube is larger than a cross-sectional area of the discharge tube. . 3. The gas laser oscillation device according to claim 1, wherein introduction portions of the second gas flow path to the discharge tube are provided at at least two opposing positions. 3. The gas laser oscillation device according to claim 1, wherein an introduction portion of the second gas flow path into the discharge tube has a slit shape over the entire circumference. The gas laser oscillation apparatus according to any one of claims 1 to 4, wherein the first gas flow path and the second gas flow path are directly branched from a heat exchanger that cools the laser gas.

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