JP2013026302A - Gas laser oscillator and laser material processing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem of a gas laser oscillator that the output drop due to deterioration of components in the oscillator after long-term use must be minimized.SOLUTION: The gas laser oscillator comprises a laser gas supply/discharge detector which detects the laser gas supply/discharge of the gas laser oscillator, a discharge input detector which detects the discharge input, a laser output detector which detects the laser output, a comparator which calculates the I/O characteristics of the gas laser oscillator by receiving the discharge input and the laser output thus received, and comparing the I/O characteristics with a preset reference characteristics, and a controller which can obtain an optimum laser gas supply/discharge by controlling a laser gas supply device and a laser gas discharge device depending on the output from the comparator.

Description

  The present invention relates to a high-power gas laser oscillation apparatus and a laser processing machine mainly used for sheet metal cutting.

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

  A laser gas 902 is filled or circulated in the laser discharge tube 901 made of a dielectric. A high voltage power supply device 905 connected to electrodes 903 and 904 provided around the laser discharge tube 901 generates a discharge 906 in the laser discharge tube 901. The laser gas 902 is excited by the discharge 906, a laser beam is generated between the total reflection mirror 907 and the partial reflection mirror 908, and a part of the laser beam 902 passes through the partial reflection mirror 908 and is output as a laser beam 909.

  A laser gas discharge port 911 and a laser gas supply port 912 connected to the gas supply / discharge control device 910 are provided around the laser discharge tube 901, and part of the laser gas deteriorated by the discharge 906 is from the laser gas discharge port 911. Control is performed so that a constant amount of new laser gas is constantly discharged from the laser gas supply port 912 at a constant amount.

  However, in order to perform a stable discharge and obtain a stable laser output, the gas laser oscillation device needs to prevent impurities from entering the laser gas from the outside atmosphere as much as possible. Therefore, the gas laser oscillation device usually has a sealed structure that is isolated from the external atmosphere.

  In addition, in order to remove the moisture adsorbed on the inner wall of the gas circulation path during the stop period, heat is applied by discharging for a certain time after startup, and the laser gas consumption is increased by a factor of about 5 for a certain time. Some oscillate (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-56221

  In the conventional laser oscillation device, the laser gas supply / discharge amount is always set to be constant. Therefore, when the input / output characteristics are reduced to a certain level due to deterioration of the components constituting the laser oscillation device, the laser oscillation device Maintenance must be performed. In general, the gas laser oscillation device is used for 50,000 hours or more in operation time. For example, the total reflection mirror and the partial transmission type reflection mirror are replaced with new ones in about 4,000 hours.

  That is, suppression of output reduction due to component deterioration of the oscillation device during long-term use has been a major issue.

  An object of the present invention is to provide a rational gas laser oscillation device that optimizes the supply and discharge amount of the laser gas according to the state of the laser oscillation device and extends the maintenance period of the laser oscillation device.

  In order to solve the above problems, a gas laser oscillator according to the present invention includes a laser discharge tube filled with a laser gas, a high-voltage power supply device that supplies discharge energy to the laser gas, and a laser gas exhaust device that discharges the laser gas in the laser discharge tube. A gas laser oscillation device comprising a laser gas supply device for supplying a new laser gas into the laser discharge tube, a laser gas supply / discharge amount detector for detecting the laser gas supply / discharge amount of the gas laser oscillator, and a discharge input detection for detecting the discharge input A comparator, a laser output detector for detecting a laser output, a calculation device for calculating the input / output characteristics of the gas laser oscillator by inputting the detected discharge input and laser output, and comparing with a preset reference characteristic; According to the output of the comparison device, the laser gas supply device and the laser gas exhaust device And a Gosuru controller. With this configuration, a decrease in laser output due to deterioration of oscillator component parts is suppressed.

  With the configuration described above, the gas laser oscillator of the present invention improves the laser gas utilization rate by optimizing the laser gas supply / discharge amount during operation of the laser oscillation device, and reduces the laser output due to the deterioration of the oscillator components. And the maintenance period can be extended.

The block diagram which shows the structure of an example of embodiment of this invention Graph showing an example of input / output characteristics of laser oscillator Configuration diagram of a laser processing machine using the gas laser oscillation device of the present invention Configuration diagram of gas laser oscillation device according to prior art

  An embodiment of the present invention is shown in FIG.

  In FIG. 1, a laser oscillating unit 101 receives a laser gas supply valve 109, a laser gas exhaust valve in response to commands from the control device 110 so that the pressure of the laser gas in the oscillating unit detected by the pressure sensor 104 becomes a preset operating pressure. 105 is opened and closed, and the supply and discharge amount of the laser gas is kept constant.

  In this state, when a discharge input is applied from the high voltage power supply device 111 to the laser oscillation unit 101, laser oscillation occurs, and the laser gas filled in the laser oscillation unit 101 gradually deteriorates. At this time, a part of the deteriorated laser gas is exhausted through the laser gas exhaust device 103, but a part circulates in the oscillator. Therefore, a part of the deteriorated laser gas is circulated at a certain rate at all times during the operation of the laser oscillation device.

  The ratio of circulating deteriorated gas is determined as follows. That is, the discharge current detected by the discharge input detector 106 and the laser output detected by the laser output detector 107 are input to the comparator 108, where the input / output characteristics are calculated, and the preset reference characteristics, that is, the optimum It is compared with the input / output characteristic F1 at the laser gas supply amount and the input / output characteristic F2 at the limit of the ratio of the deteriorated gas to be circulated.

  When the ratio of the circulated deteriorated gas exceeds the limit, the supply amount of fresh laser gas is increased, and the deteriorated laser gas circulated in the oscillation unit is gradually diluted to decrease the ratio of the deteriorated gas.

  At this time, the gas is exhausted while being balanced with the supply of the laser gas in order to keep the gas pressure in the oscillation unit constant.

  In this case, in order to make the exhaust amount by the laser gas exhaust device 103 coincide with the supply amount from the laser gas supply device 102, the laser gas exhaust valve is connected via the control device 110 so that the internal pressure of the oscillation unit detected by the pressure sensor 104 becomes the operating pressure. The opening / closing operation 105 is performed.

  Further, the laser gas discharge amount is monitored by the laser gas supply / discharge amount detector 112, and the discharge amount when the laser output is recovered to the input / output characteristic F1 is stored in the control device 110, and the increase in the supply / discharge amount of the laser gas is increased. And the continuous operation is performed again with a constant laser gas supply / discharge amount newly stored in the control device.

  Thus, by performing the cycle operation that repeats the two operation modes, it is possible to operate with the optimum gas consumption according to the state of the laser oscillation device, and the reflecting mirror constituting the oscillator as compared with the conventional laser oscillator Such a maintenance period can be made long.

  Next, FIG. 3 is a block diagram of the gas laser processing machine in the embodiment of the present invention. The laser beam 114 output from the gas laser oscillation device 113 of the present invention is guided to the condensing lens 117 provided in the torch 116 by the reflecting mirror 115, and the laser beam 118 condensed by the condensing lens 117 is processed as a workpiece 119. Is used for applications such as cutting and welding.

  The workpiece 119 is mounted on the table 120, and the workpiece 119 is machined into an arbitrary shape by moving the condenser lens 117 with the power 121 and the power 122. In FIG. 3, the condensing lens 117 is moved by the power 121 or the power 122, but the same effect can be obtained even if the power 121 or the power 122 is connected to the table 120 and moved.

  The gas laser oscillation apparatus and gas laser processing machine according to the present invention can efficiently use laser gas, and can significantly reduce the periodic inspection and replacement costs of oscillator components such as reflectors, thereby reducing running costs. It is useful as a gas laser oscillator and a gas laser processing machine.

DESCRIPTION OF SYMBOLS 101 Laser oscillation part 102 Laser gas supply apparatus 103 Laser gas exhaust apparatus 104 Pressure sensor 105 Laser gas exhaust valve 106 Discharge input detector 107 Laser output detector 108 Comparison apparatus 109 Laser gas supply valve 110 Control apparatus 111 High voltage power supply apparatus 112 Laser gas supply discharge amount detection 113 Gas laser oscillator 114 Laser beam 115 Reflective mirror 116 Torch 117 Condensing lens 118 Condensed laser beam 119 Workpiece 120 Table 121 Power 122 Power 901 Laser discharge tube 902 Laser gas 903 Electrode 904 Electrode 905 High voltage power supply 906 Discharge 907 Total reflection mirror 908 Partial reflection mirror 909 Laser beam 910 Gas supply / discharge control device 911 Laser gas discharge port 912 Laser gas supply port

Claims (3)

A laser discharge tube filled with laser gas, a high voltage power supply device for supplying discharge energy to the laser gas, a laser gas exhaust device for discharging laser gas in the laser discharge tube, and a laser gas supply device for supplying new laser gas into the laser discharge tube A gas laser oscillation device comprising:
Laser gas supply / discharge amount detector for detecting laser gas supply / discharge amount of gas laser oscillator, discharge input detector for detecting discharge input, laser output detector for detecting laser output, and laser gas supply / discharge for detecting laser gas supply / discharge amount A quantity detector; a comparator that inputs the detected discharge input and laser output to calculate the input / output characteristics of the gas laser oscillator; and compares the input and output characteristics with a preset reference characteristic; and the comparator according to the output of the comparator A gas laser oscillation device comprising: a laser gas supply device; and a control device for controlling the laser gas exhaust device. When the calculated input / output characteristic exceeds the limit reference characteristic of the deteriorated gas ratio, the controller increases the laser gas supply / discharge amount by the linked operation of the laser gas supply device and the exhaust device, and recovers to the normal reference characteristic. 2. The gas laser oscillation apparatus according to claim 1, wherein at the time when the supply / discharge amount is stopped, the increase in the supply / discharge amount is stopped and the supply / discharge amount is controlled to be constant again. A laser processing machine comprising the gas laser oscillation device according to claim 1.

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