JP2006012876A - Gas laser oscillation equipment and gas laser beam machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide highly reliable equipment in which magnification of a fault especially due to plugging of piping etc. can be prevented, and which can stably be used for long time in laser oscillation equipment using a blower and in a laser beam machine. <P>SOLUTION: Equipment is provided with a main exhaust mechanism 25 having at least one or more valves exhausting laser gas from a laser gas passageway 10, an auxiliary exhaust mechanism 26 exhausting laser gas from the driving part 22 of a blast means, and a controller 30 detecting the opening/closing period of a supply valve 31 of laser gas. A means is installed for detecting an opening/closing period of the supply valve 31 when the valve of the main exhaust mechanism 25 is opened and closed and comparing a value when the valve is opened and a value when the valve is closed so as to generate an alarm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas laser oscillation device that circulates a laser gas by a blower and a gas laser processing machine.

  A conventional laser oscillation device that circulates laser gas using a blower is configured such that oil in a drive portion of the blower does not leak into the laser gas (see, for example, Patent Document 1).

  FIG. 7 is a configuration diagram of a conventional laser oscillation device 120.

  In FIG. 7, the conventional laser oscillation device 120 includes a blower 108 for circulating laser gas, a gas piping path 103 for circulating the laser gas, and a laser gas supply means for supplying laser gas to the gas piping path 103. A normal discharge side solenoid valve 112 connected in series to a certain supply side solenoid valve 110 and a laser gas cylinder 130 arranged outside the apparatus, and a flow restrictor 111 which is a laser gas discharge means for discharging the laser gas in the gas piping path 103, and rapid discharge A side solenoid valve 113 and an exhaust pump 114, and a flow path limiter 111, which is a motor chamber decompression means for decompressing the motor chamber 108c in the blower 108, and an oil trap 116 connected to a rapid discharge side solenoid valve 113. In the laser oscillation device 120, the impeller chamber of the blower 108. The differential pressure detection means 145 for detecting the pressure difference between 08b and the motor chamber 108c, and the differential pressure lower limit reference value set in advance with the minimum pressure difference between the impeller chamber 108b and the motor chamber 108c of the blower 108 as the differential pressure lower limit reference value. A setting unit 144; a differential pressure lower limit comparison unit 143 that compares an output signal of the differential pressure detection means 145 and a differential pressure lower limit reference value set in the differential pressure lower limit reference value setting unit 144; A differential pressure upper limit reference value setting unit 147 in which the maximum pressure difference between the impeller chamber 108b and the motor chamber 108c is set as a differential pressure upper limit reference value, an output signal of the differential pressure detecting means 145, and the differential pressure upper limit reference value setting unit. The differential pressure upper limit comparison unit 146 that compares the differential pressure upper limit reference value set in 147, and the integration means 14 that counts or integrates the outputs of the differential pressure lower limit comparison unit 143 and the differential pressure upper limit comparison unit 146. If has a difference pressure monitoring device 150 having an alarm means 141 the output of the integration means 142 to generate an alarm when it exceeds a predetermined value.

FIG. 8 is a configuration diagram around the fan 108 means of the conventional gas laser oscillation device 120. The blower 108 is roughly divided into an impeller chamber 108b having an impeller 108a for circulating laser gas at high speed and a motor chamber 108c having a motor for rotating the impeller 108a at high speed. A seal 108d is inserted between the impeller chamber 108b and the motor chamber 108c so that the lubricating oil 108e in the motor chamber 108c does not leak into the impeller chamber 108b.
JP 2003-110170 A

  The above-described conventional laser oscillation device can prevent the oil mist from adhering to the piping and the solenoid valve, but has a problem that the structure is complicated and the cost is increased.

  In addition, pipe clogging, in which liquefied oil adheres and solidifies in the pipe and clogs the pipe over time, can be easily recovered by performing maintenance. It was.

  In order to solve the above-described problems, the present invention provides a discharge means for exciting laser gas, a blower means for blowing laser gas, a laser gas path forming a laser gas circulation path between the discharge means and the blower means, and the blower A drive unit for driving the means; a supply mechanism including at least one valve for supplying laser gas to the laser gas path; and at least one valve for discharging laser gas from the laser gas path. A main discharge mechanism; a sub-discharge mechanism that discharges laser gas from the drive unit; and a means for detecting a total of the main discharge mechanism and the sub-discharge mechanism or a laser gas discharge amount of the sub-discharge mechanism. A control device is provided for comparing the amount of laser gas discharged at each time of opening and closing.

  According to the present invention, a highly reliable gas laser oscillation device and gas laser processing machine that can be used stably over a long period of time can be provided at low cost.

  FIG. 5 shows an example of a schematic configuration of an axial flow type gas laser oscillation apparatus using the embodiment of the present invention.

  In FIG. 5, 1 is a discharge tube made of a dielectric material such as glass, and 2 and 3 are electrodes provided around the discharge tube. Reference numeral 4 denotes a power source connected to the electrode. Reference numeral 5 denotes a discharge space in the discharge tube 1 sandwiched between the electrodes 2 and 3. Reference numeral 6 denotes a total reflection mirror, and reference numeral 7 denotes a partial reflection mirror. The total reflection mirror 6 and the partial reflection mirror 7 are fixedly arranged at both ends of the discharge space 5 to form an optical resonator. Reference numeral 8 denotes a laser beam output from the partial reflecting mirror 7. An arrow 9 indicates the direction in which the laser gas flows, and circulates in the axial flow type gas laser oscillation device. 10 is a laser gas flow path, 11 and 12 are heat exchangers for lowering the temperature of the laser gas whose temperature has been increased by discharge in the discharge space 5 and the operation of the blower, and 13 is a blower means for circulating the laser gas. A gas flow of about 100 m / sec is obtained in the discharge space 5 by the means 13. The laser gas flow path 10 and the discharge tube 1 are connected by a laser gas introduction part 14.

  Next, an example of a schematic configuration of a laser processing machine using the embodiment of the present invention is shown in FIG.

  In FIG. 6, the laser beam 8 is reflected by the reflecting mirror 15 and guided to the vicinity of the workpiece 16. The laser beam 8 is condensed into a high-density energy beam by a condensing lens 18 provided inside the torch 17, irradiated onto the workpiece 16, and processed. The workpiece 16 is fixed on the machining table 19, and the torch 17 is moved relative to the workpiece 16 by the X-axis motor 20 or the Y-axis motor 21, whereby a predetermined shape is machined.

  The laser gas sent out from the air blowing means 13 passes through the laser gas flow path 10 and is introduced into the discharge tube 1 from the laser gas introduction part 14. In this state, a discharge is generated in the discharge space 5 from the electrodes 2 and 3 connected to the power source 4. The laser gas in the discharge space 5 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 6 and the partial reflection mirror 7. Beam 8 is output. This laser beam 8 is used for applications such as laser processing.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a main part of a laser oscillation apparatus according to an embodiment of the present invention.

  The gas pressure in the laser gas flow path is constantly monitored by a gas pressure sensor 28, and the gas pressure sensor 28 and the gas supply mechanism 29 are connected to a control device 30. By controlling the gas supply mechanism 29 with the control device 30, fresh laser gas is supplied from the outside by the gas supply mechanism 29 so as to compensate for the amount discharged from the two discharge mechanisms, and the gas pressure in the laser gas flow path is increased. Is always kept constant.

  Normally, the gas supply mechanism 29 is provided with a supply valve 31, and when the gas pressure in the laser gas flow path becomes a certain value or less, the valve is opened by the gas pressure control device 30, and the gas is introduced into the laser gas flow path. Is supplied. When the gas pressure in the laser gas flow path exceeds a certain value due to gas supply, the valve is closed.

  A discharge valve 32 is provided in the laser gas discharge path of the main discharge mechanism 25. The discharge valve 32 is always open, and a certain amount of laser gas passes through it.

  For example, about 10 L / h of gas is constantly discharged from the vacuum pump 27. This breakdown is a ratio of about 9 L / h from the main discharge mechanism 25 and about 1 L / h from the sub discharge mechanism 26. The sub discharge path is set smaller than the main discharge path, and is designed by design so that a difference in discharge amount occurs due to a difference in path resistance. As the gas is discharged from the vacuum pump 27, the pressure in the laser gas passage 10 decreases. This pressure is constantly monitored by the gas pressure sensor 28, and the supply valve 31 is opened and closed to replenish the reduced amount of gas. The operation of the supply valve 31 is as follows. When the gas pressure becomes a certain value, for example, 20.0 kPa or less, an open signal is issued from the control device 30 to the supply valve 31, and supply of gas is started. By supplying the gas, the pressure in the laser gas flow path reaches a certain value, for example, 21.0 kPa in about 0.5 seconds, and the supply valve 31 is closed. Regardless of whether the supply valve is opened or closed, the gas is continuously discharged from the vacuum pump 27. When the supply valve 31 is closed, the pressure in the laser gas flow path gradually decreases from 21.0 kPa and decreases to 20.0 kPa in about 19 to 20 seconds. When the pressure reaches 20.0 kPa, the supply valve 31 opens again. Therefore, this repeated cycle, that is, the opening / closing cycle of the supply valve is about 20 seconds. If the amount of gas discharged from the vacuum pump 27 decreases for some reason, the rate of pressure decrease per unit time in the laser gas flow path also decreases, and the opening / closing cycle of the supply valve 31 also increases. For example, when the gas discharge amount from the vacuum pump 27 is changed from about 10 L / h in the normal state to about 5 L / h, the opening / closing cycle of the supply valve 31 is also extended from about 20 seconds to about 40 seconds. That is, if the control device 30 monitors the opening / closing cycle of the supply valve 31, the amount of gas discharged from the vacuum pump 27 can be obtained indirectly.

  Here, consider the case where the sub-discharge path 26 is clogged with oil over time. Since the discharge amount from the sub discharge path 26 is very small compared to the main discharge path 25, even if the sub discharge path 26 is clogged and the discharge amount is reduced, the discharge amount from the main discharge path is correspondingly reduced. The gas discharge amount from the vacuum pump 27 remains at 10 L / h and hardly changes. Therefore, even if the gas discharge amount from the vacuum pump 27 is directly monitored or indirectly monitored using the opening / closing cycle of the supply valve 31 as described above, a change in the gas discharge amount is detected due to the clogging of the sub discharge path 26. It is very difficult to do. Even if a certain value is set as the threshold, there is a high possibility of malfunction and it cannot be said that it is practical.

  The point of this embodiment resides in the discharge valve 32 provided in the main discharge mechanism 25. Normally, the discharge valve 32 remains open, but the discharge valve 32 is closed for a certain time during operation. Then, the discharge from the vacuum pump 27 is only the sub discharge path 26. In a state where there is almost no clogging due to oil mist or the like in the sub discharge path 26, the discharge amount from the vacuum pump 27 remains at 10 L / h and hardly changes. This is because the pressure balance naturally changes so that the gas that was originally discharged from the main discharge path 25 is discharged from the sub-discharge path. On the other hand, when the sub discharge path 26 is almost completely clogged with oil mist or the like, when the discharge valve 32 is closed, the amount of gas discharged from the vacuum pump 27 is greatly reduced from the initial state of 10 L / h, for example. Decrease to 1-2 L / h.

  Therefore, the amount of gas discharged from the vacuum pump 27 when the discharge valve 32 is opened and closed is monitored by the control device 30 and compared with each other, or by comparing with a predetermined value, The clogging of the mechanism 26 can be detected. At this time, an alarm is issued from the control device 30 to prompt the user to clean the sub-piping mechanism 26, so that oil mist emitted from the oil 32 in the drive unit 22 can enter the laser gas flow path 10 in advance. Can be prevented.

  In addition, although the inventors abolished the main discharge mechanism 25 itself and examined the plan which discharges | emits a laser gas only by the sub discharge mechanism 26 from the beginning, in this case, the pressure of the ventilation means 13 part and the drive part 22 is examined. It is considered that the difference can always be secured above a certain level and is effective against the oil mist entering the laser gas flow path. However, the separated laser gas, which is the function of the original main discharge mechanism, is reduced to about 10 L / It becomes difficult to play the role of continuing to discharge. This is because it is very difficult to realize gas discharge on the order of 10 L / h because the sub-discharge mechanism forms a laser gas flow through the partition wall 24 having a gap of only several tens of μm.

  In the present embodiment, the period for closing the discharge valve 32 to detect clogging of the sub-discharge mechanism is sufficient for several minutes, and determination can be made within that period. By performing this determination sequence once every few hours during normal operation, clogging of the sub piping mechanism 26 can be detected. When the discharge valve 32 is closed for a long time (several tens of minutes or more), secondary disasters such as a decrease in laser output due to insufficient discharge of the separated laser gas can be considered.

  In the present embodiment, as a means for detecting a change in the amount of gas discharged from the vacuum pump 27, as shown in FIG. In addition, it is also possible to provide a flow sensor 34 downstream of the joining position of the main discharge mechanism and the sub discharge mechanism as shown in FIG. 2 or in the middle of the sub discharge mechanism as shown in FIG. Alternatively, as shown in FIG. 4, it is possible to provide pressure detection ports at two locations of the sub-discharge mechanism and detect the flow rate by the pressure difference.

  INDUSTRIAL APPLICABILITY According to the present invention, a gas laser oscillation device and a gas laser processing machine using a blower are industrially useful because they can provide high reliability that can be used stably over a long period of time with an inexpensive configuration.

Configuration diagram of main parts of laser oscillation apparatus and laser beam machine according to embodiments of the present invention The block diagram of the principal part of the laser oscillation apparatus of another embodiment of this invention and a laser beam machine The block diagram of the principal part of the laser oscillation apparatus of another embodiment of this invention and a laser beam machine The block diagram of the principal part of the laser oscillation apparatus of another embodiment of this invention and a laser beam machine Configuration diagram of gas laser oscillator Configuration diagram of gas laser processing machine Configuration diagram of conventional gas laser oscillator Configuration diagram of the main part of the blowing means of a conventional gas laser oscillator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge tube 2 Electrode 3 Electrode 4 Power supply 5 Discharge space 6 Total reflection mirror 7 Partial reflection mirror 8 Laser beam 9 Laser gas flow direction 10 Laser gas flow path 11 Heat exchanger 12 Heat exchanger 13 Blower 14 Laser gas introduction part 15 Reflector 16 Work 17 Torch 18 Condensing lens 19 Processing table 20 X-axis motor 21 Y-axis motor 22 Drive part 23 Axis 24 Bulkhead part 25 Main discharge mechanism 26 Sub-discharge mechanism 27 Vacuum pump 28 Gas pressure sensor 29 Gas supply mechanism 30 Control device 31 Supply Valve 32 Drain valve 33 Oil 34 Flow sensor 35 Pressure port

Claims (11)

Discharge means for exciting laser gas, blower means for blowing laser gas, laser gas path forming a circulation path of laser gas between the discharge means and blower means, a drive unit for driving the blower means, and the laser gas path A supply mechanism having at least one valve for supplying laser gas to the main body, a main discharge mechanism having at least one valve for discharging laser gas from the laser gas path, and laser gas from the drive unit. A sub-discharge mechanism for discharging and a means for detecting a total of the main discharge mechanism and the sub-discharge mechanism or a laser gas discharge amount of the sub-discharge mechanism, and a laser gas discharge amount when the valve of the main discharge mechanism is opened and closed, respectively. A gas laser oscillation device provided with a control device for comparing the two. A valve opening / closing cycle detection unit for the supply mechanism is provided, and the control device compares signals from the valve opening / closing cycle detection unit for the supply mechanism when the valve of the main discharge mechanism is opened and closed. The gas laser oscillation apparatus according to 1. 2. The gas laser oscillation apparatus according to claim 1, wherein a flow rate sensor for measuring a flow rate after joining the main discharge mechanism and the sub discharge mechanism is used as the laser gas discharge amount detection means. The gas laser oscillation apparatus according to claim 1, wherein a flow rate sensor for measuring a flow rate is used for the sub-discharge mechanism as the laser gas discharge amount detection means. The gas laser oscillation apparatus according to claim 1, wherein the laser gas discharge amount detection means includes a gas pressure detection means and a means for performing a calculation based on a signal from the gas pressure detection means at at least two locations of the sub discharge mechanism. Discharge means for exciting laser gas, blower means for blowing laser gas, laser gas path forming a circulation path of laser gas between the discharge means and blower means, a drive unit for driving the blower means, and the laser gas path A supply mechanism having at least one valve for supplying laser gas to the main body, a main discharge mechanism having at least one valve for discharging laser gas from the laser gas path, and laser gas from the drive unit. A sub-discharge mechanism for discharging and a means for detecting a total of the main discharge mechanism and the sub-discharge mechanism or a laser gas discharge amount of the sub-discharge mechanism, and a laser gas discharge amount when the valve of the main discharge mechanism is opened and closed, respectively. A gas laser processing machine provided with a control device for comparing the two. A valve opening / closing cycle detection means of the supply mechanism, and the signals from the valve opening / closing cycle detection means of the supply mechanism when the valve of the main discharge mechanism is opened and closed are compared with each other or with a predetermined value. The gas laser processing machine according to claim 6, further comprising means for comparing and generating an alarm. A valve opening / closing cycle detection unit for the supply mechanism is provided, and the control device compares signals from the valve opening / closing cycle detection unit for the supply mechanism when the valve of the main discharge mechanism is opened and closed. 6. The gas laser processing machine according to 6. 7. The gas laser processing machine according to claim 6, wherein a flow rate sensor for measuring a flow rate after joining the main discharge mechanism and the sub discharge mechanism is used as the laser gas discharge amount detection means. The gas laser processing machine according to claim 6, wherein a flow rate sensor for measuring a flow rate is used for the auxiliary discharge mechanism as the laser gas discharge amount detection means. 7. The gas laser processing machine according to claim 6, wherein as the laser gas discharge amount detection means, a gas pressure detection means and means for performing calculation based on a signal from the gas pressure detection means are provided in at least two places of the sub discharge mechanism.