JP2019192792A - Gas laser oscillation method, gas laser oscillation device using this method, laser deposition device, and laser processing device - Google Patents

Abstract

To provide a laser beam generation device forming a laser beam having a waveform with a flat laser output part at a timing before and after of a steeple pulse by combining smoothly a steeple pulse waveform and a flat waveform.SOLUTION: A first electric discharge tube 10 in which a first excitation gas is filled and a second electric discharge tube 20 in which a second excitation gas is filled are arranged in serial. In an outer side of one of the first electric discharge tube 10 and the second electric discharge tube 20, a rear miller (entire reflection miller) is arranged, and on the other outer side, a half miller (semi-reflection miller) is arranged. A pulse is applied from a pulse power supply 11 to the first electric discharge tube 10, and the pulse is applied from a pulse power supply 21 to the second electric discharge tube 20. Thus, a laser beam to which a flat laser waveform and an a steeple-like pulse waveform are added is generated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas laser oscillation method and a gas laser oscillation apparatus, a laser welding apparatus, and a laser processing apparatus using the method, and more specifically, based on a first output waveform and a second output waveform of laser light. The present invention relates to a gas laser oscillation method for oscillating a laser beam having a third output waveform in which both output waveforms are combined, and a gas laser oscillation device, a laser welding device, and a laser processing device using this method. More specifically, a gas laser oscillation method for oscillating a laser beam having a third output waveform combining both output waveforms based on the flat first output waveform of the laser beam and the pulsed second output waveform, The present invention also relates to a gas laser oscillation device, a laser welding device, and a laser processing device using this method.

In a conventional axially excited short pulse carbon dioxide laser device, an excitation medium gas (laser gas, hereinafter abbreviated as “laser gas”) in which carbon dioxide, nitrogen gas, and helium gas are mixed as a laser medium in a discharge tube made of an insulator such as glass. The main electrode is provided in the discharge tube, and a main power source is connected to the main electrode so as to generate a discharge in the discharge tube. Fast electrons generated by this discharge, excites the N ₂ molecules raised to a high energy level, the excited N ₂ molecules, excited by energizing the CO ₂ molecule collides with the CO ₂ molecule , Raise the energy level. At that time, the energy level of the N ₂ molecule decreases. Inverted distribution of CO ₂ molecules is amplified in the resonator by a rear mirror (total reflection mirror) and a half mirror (partial reflection mirror) arranged to face both ends of the discharge tube, and stimulates and emits laser light. A laser beam is output to the outside (see, for example, Patent Document 1).

  FIG. 16 shows the output waveform of the laser beam output from the conventional axially excited short pulse carbon dioxide laser device. In FIG. 16, the laser intensity (W) is plotted on the vertical axis and time is plotted on the horizontal axis, and the laser light output waveform is shown. When the output of the laser beam is started, the laser intensity in FIG. 16 suddenly rises from the O point (time t1) to the P point as a spire pulse, and then decreases. The state of decrease is that the laser intensity gradually decreases so as to pull the pulse tail (tail) after it has decreased to Q point (time t2) of the laser intensity that is less than half of the peak P of the spire pulse. The laser beam intensity shifts to S point (time t3) where the laser intensity is zero. The general output waveform of the laser beam is a shape in which the points O, P, Q, and S are connected by lines in FIG.

  On the other hand, as an industrial utilization method of laser light, laser welding is performed by irradiating a plurality of superimposed synthetic resin materials, or holes are formed by irradiating a synthetic resin material with laser light. .

  For example, when laser welding a synthetic resin material, an opaque or colored laser light absorbing resin material 81 is disposed under a transparent laser light transmitting resin material 80 as shown in FIG. Laser light 50 is irradiated from above the resin material 80.

  The laser beam 50 is absorbed by the laser beam absorptive resin material 81, and the laser beam absorptive resin material 81 is melted to form a melted portion 83 inside. The surface 83a of the melted portion 83 is melted with the facing surface 80a of the laser light transmitting resin material 80 facing and abutting, and when the irradiation with the laser light 50 stops, the surface 83a is cooled and solidified to be welded.

  However, as depicted in FIG. 17 with the surface irregularities of the laser light transmitting resin material 80 and the laser light absorbing resin material 81 being emphasized, the laser light transmitting resin material 80 and the laser light absorbing resin material 81 are respectively shown. The surface 80a and the surface 83a are in close contact with each other when the degree of close contact is weak, such as when the surface roughness of the surface is rough or warped and a gap is formed between a part of the surface 80a and the surface 83a described above. It takes time to melt together. Even if the opposed surface 80a and the surface 83a are in close contact, the contact strength that is lightly in contact with the surface 80a cannot provide quick and reliable welding, and the welding strength after the welding operation may be insufficient.

  Therefore, conventionally, when laser welding of a synthetic resin material is performed, the range to be welded between the laser light transmitting resin material 80 and the laser light absorbing resin material 81 is set to heater heating, electromagnetic induction heating, hot air heating, infrared lamp heating, etc. After preheating with the above means, the laser light transmitting resin material 80 and the laser light absorptive resin material 81 are brought into close contact with each other, and then laser beam is irradiated to perform reliable welding promptly to obtain a desired welding strength. It has been proposed to obtain (see, for example, Patent Document 2).

  That is, as shown in FIG. 18A, preheating is performed with another heat source before the laser light irradiation (at time t0 to t1). Then, even if the surface roughness of the laser light transmitting resin material 80 and the laser light absorbing resin material 81 is rough, the welding target range of the laser light transmitting resin material 80 and the laser light absorbing resin material 81 is softened by preheating. And stick. When the laser beam 50 is irradiated, the laser beam-absorbing resin material 81 melts in a close contact state. The surface 83a of the melted portion 83 and the facing surface 80a of the laser light transmitting resin material 80 are melted together, and when the irradiation with the laser light 50 stops, the surface 83a is cooled, solidified and welded. As shown in FIG. 18A, reliable laser welding can be performed quickly when preheating is performed.

  Here, if the laser beam having a waveform as shown in FIG. 18A, that is, a waveform shown by a dotted line in FIG. With an apparatus having one laser beam output means that is not provided with any other preheating means, it is possible to quickly and reliably perform laser welding or perform various other types of laser processing.

  However, in the conventional gas laser oscillation apparatus, the laser corresponding to the preheating is used before the normal laser beam waveform (a waveform in which the points O, P, Q, and S are connected by lines) as shown in FIG. It was difficult to add an optical output waveform.

  For example, in a conventional gas laser oscillation apparatus, as shown in FIG. 19, a gas laser oscillator having a plurality of discharge regions D1, D2,... D5 in one discharge tube (laser tube) simultaneously applies a pulse voltage to each discharge region. It was applied with a target or appropriate phase difference. As described above, a pulse shaping method of a pulse laser that performs laser oscillation in each discharge region to arbitrarily form a waveform of a laser output pulse has been known (see Patent Document 3).

  However, since one type of excitation gas flows through one discharge tube, one type of laser beam with a waveform is output. In the apparatus of FIG. 19, the discharge timing of the pair of adjacent electrodes C (C1 to C5) and electrodes A (A1 to A5) is shifted to make the waveform of the laser beam. The waveform is shown in FIG. It was difficult to do as shown by the dotted line.

  In addition, as shown in FIG. 20, a gas laser oscillation device in which a plurality of discharge tubes for flowing the same excitation gas between a total reflection mirror and a semi-reflection mirror (partial mirror) is also known. In a plurality of discharge tubes that flow, laser light having one type of waveform is output. The laser beam waveform is shown by the dotted line in FIG. 18B, although the laser beam output can be varied by increasing / decreasing the laser beam output intensity by combining ON / OFF of the discharge for each of the plurality of discharge tubes. As described above, the waveform of the laser beam was not arbitrarily created (see Patent Document 4).

JP 2000-301477 A JP 2004-74734 A Japanese Patent Application Laid-Open No. 61-14785 Japanese Utility Model Publication 2-140865

  The present invention uses a gas laser oscillation method for oscillating a laser beam having a third output waveform obtained by combining both output waveforms based on the first output waveform and the second output waveform of the laser beam, and this method. It is an object to provide a gas laser oscillation device, a laser welding device, and a laser processing device.

  More specifically, a gas laser oscillation method for oscillating a laser beam having a third output waveform combining both output waveforms based on the flat first output waveform of the laser beam and the pulsed second output waveform, It is another object of the present invention to provide a gas laser oscillation device, a laser welding device, and a laser processing device using this method.

  In particular, the present invention uses a plurality of excitation gases to oscillate a laser beam having a third output waveform obtained by combining both output waveforms based on the first output waveform and the second output waveform of the laser beam. It is an object of the present invention to provide a gas laser oscillation method, and a gas laser oscillation device, a laser welding device, and a laser processing device using the method.

  In order to achieve the above-described problem, in the gas laser oscillation device according to the present invention, a first excitation gas is inserted between a rear mirror and a half mirror which are opposed to each other by a predetermined resonator length (L). And the second discharge tube containing the second excitation gas are arranged in series, the first discharge tube is discharged using the oscillation trigger means of the first pulse power source, and the second discharge tube It was configured to generate a laser beam having a flat waveform and a spire-shaped pulse waveform by discharging using an oscillation trigger means of a pulse power source.

  By arbitrarily setting the timing to operate the oscillation trigger means of the second pulse power supply of the second discharge tube with respect to the timing of operating the oscillation trigger means of the first pulse power supply of the first discharge tube, The position of the spire-shaped pulse waveform added to the various waveforms can be arbitrarily set.

  In the gas laser oscillation device according to the present invention, a gas obtained by mixing, for example, carbon dioxide gas, nitrogen, and helium at a volume ratio of 1: 3: 4 is put in the first discharge tube as the first excitation gas. A flat waveform is formed, and a gas obtained by mixing, for example, carbon dioxide gas, nitrogen, and helium as a second excitation gas in a volume ratio of 20: 1: 5 to 40 in the second discharge tube. To make a spire pulse-like waveform.

  A first discharge tube containing a first excitation gas between a rear mirror (total reflection mirror) 1 and a half mirror (half reflection mirror) 2 which are opposed to each other by a resonator length (L); A second discharge tube containing two excitation gases is arranged in series, and is amplified between the rear mirror 1 and the half mirror 2 through the first discharge tube and the second discharge tube. A laser beam having a waveform added with the waveform is output.

  When laser welding is performed by the gas laser oscillation device according to the present invention, for example, the laser beam of the flat waveform portion irradiates the contact surface of the object to be welded and preheats, and then has a spire pulse-like waveform. It is also possible that the contact surface of the object to be welded is strongly irradiated and melted by the laser beam, and then the laser beam of the flat corrugated portion irradiates and heats the object to be welded to weld the object to be welded.

  When the synthetic resin material or the glass material is drilled by the gas laser oscillation device according to the present invention, for example, the laser beam of the flat corrugated portion irradiates the object to be processed to a certain degree of preheating, and the spire pulse shape immediately The laser beam with the waveform of (2) strongly irradiates the workpiece and opens a hole, and then the laser beam of the flat waveform portion irradiates and heats the workpiece and the workpiece after the drilling is scattered and sag. It is also possible to suppress the degree of occurrence.

  In the gas laser oscillation device according to the present invention, three or more discharge tubes are arranged in series between the rear mirror and the half mirror, and a dedicated excitation gas is put in each discharge tube, and each discharge tube is operated. The added waveform can be added. This enables the gas laser oscillation apparatus according to the present invention to output laser light with a desired waveform.

  According to the present invention, it is possible to provide a gas laser oscillation method for producing a laser beam having a flat laser output portion before or after a spire pulse, to which a flat waveform and a spire pulse-like waveform are added. Yes.

  In particular, the present invention can provide a new gas laser oscillation method using a plurality of excitation gases.

  Further, the present invention can provide a gas laser oscillation apparatus that uses this gas laser oscillation method to produce laser light having a waveform with a flat laser output portion before or after the spire pulse.

  The present invention also provides a synthetic resin material laser welding device, a synthetic resin material, a glass laser processing device for forming a hole in a glass material or a glass block, or forming a groove or a recess using the gas laser oscillation device. It is possible to do.

1 is a configuration diagram of a gas laser oscillation device according to a first embodiment of the present invention. (A) (b) The output waveform of the laser beam output from the gas laser oscillation apparatus concerning Embodiment 1 of this invention. (A) The figure which showed typically an example of the mixing ratio of the 1st excitation gas put into the 1st discharge tube of the gas laser oscillation apparatus concerning Embodiment 1 of this invention, (b) The figure shown to (a) The figure which measured and showed the waveform of the laser beam produced with one excitation gas. (A) The figure which showed typically an example of the mixing ratio of the 2nd excitation gas put into the 2nd discharge tube of the gas laser oscillation apparatus concerning Embodiment 1 of this invention, (b) The figure shown to (a) The figure which measured and showed the waveform of the laser beam which arose by two excitation gas. The figure which showed the waveform of the laser beam which added the waveform of the 1st and 2nd discharge tube in the gas laser oscillation apparatus concerning Embodiment 1 of this invention. The figure which showed the waveform of the laser beam which added the waveform of the 1st and 2nd discharge tube in the gas laser oscillation apparatus concerning Embodiment 1 of this invention. (A)-(d) Using the gas laser oscillation apparatus concerning Embodiment 1 of this invention, the cross section of the process of laminating | stacking a laser beam transparent resin material and a laser beam absorption resin material, and the laser beam output timing is shown. The figure shown as a pair. (A)-(d) The figure which showed the cross section of the process drilled in a laser beam absorptive resin material using the gas laser oscillation apparatus concerning Embodiment 1 of this invention, and the output timing of a laser beam in pairs. . The block diagram of the gas laser oscillation apparatus concerning Embodiment 2 of this invention. (A) The figure which showed the waveform of the laser beam which can be produced with the 1st discharge tube concerning Embodiment 2 of this invention, (b) The waveform of the laser beam which can be produced with the 2nd discharge tube concerning Embodiment 2 of this invention The figure shown, (c) Waveform of the laser beam formed by the third discharge tube according to the second embodiment of the present invention, (d) From the first discharge tube to the third discharge tube according to the second embodiment of the present invention The figure which showed the output waveform of the laser beam made by adding a waveform. (A) The figure which showed the waveform of the laser beam which can be performed with the 1st discharge tube concerning the modification of Embodiment 2 of this invention, (b) With the 2nd discharge tube concerning the modification of Embodiment 2 of this invention The waveform of the laser beam that can be produced, (c) the waveform of the laser beam that can be produced by the third discharge tube according to the modification of the second embodiment of the present invention, and (d) the modification of the second embodiment of the present invention. The figure which showed the output waveform of the laser beam formed by adding the waveform of the 1st to 3rd discharge tube. The block diagram of the gas laser oscillation apparatus concerning Embodiment 3 of this invention. (A) The figure which showed the waveform of the laser beam which can be produced by the 1st discharge tube concerning Embodiment 3 of this invention, (b) The waveform of the laser beam which can be produced by the 2nd discharge tube concerning Embodiment 3 of this invention The figure shown, (c) The waveform of the laser beam formed by the third discharge tube according to the third embodiment of the present invention, (d) The waveform of the laser beam formed by the fourth discharge tube according to the third embodiment of the present invention, (E) The figure which showed the output waveform of the laser beam formed by adding the waveform of the 1st to 4th discharge tube. The figure which showed the state in the drilling work of the gas laser processing apparatus drilled in the glass material concerning Embodiment 4 of this invention. The expanded sectional view of the glass drilled with the gas laser processing apparatus drilled in the glass material concerning Embodiment 4 of this invention. The figure which showed an example of the waveform of the pulse of the conventional laser beam. The figure which showed the state which laminated | stacked the laser beam transmission resin material and the laser beam absorption resin material by the conventional laser welding method, and was welded. (A) The figure which showed typically the part to which the energy of preheating is added to the waveform of the pulse of the conventional laser beam, (b) The part added with the energy of preheating of (a) is the waveform of the pulse of the laser beam The figure which showed the waveform when it incorporates into a dotted line. The block diagram of the other conventional gas laser oscillation apparatus. The block diagram of the further another conventional gas laser oscillation apparatus.

  The gas laser oscillation method of the present invention includes a plurality of excitation gases obtained by mixing carbon dioxide, nitrogen and helium gases at different mixing ratios, two or more discharge tubes, a rear mirror (total reflection mirror), and a half mirror (half reflection mirror). And a laser beam excitation power source, an oscillation trigger unit of the laser beam excitation power source, and a laser beam excitation control unit, the excitation gases having different mixing ratios are put into the two or more discharge tubes, and only a predetermined resonator length (L) is obtained. The discharge tubes are arranged in series between the rear mirror and the half mirror that are spaced apart from each other with the longitudinal axis aligned, and the laser light excitation control means includes the laser light excitation power source and the laser light excitation power source. The oscillation trigger means is controlled to oscillate laser light in the discharge tube between the rear mirror and the half mirror, and the wave of the laser light generated by each discharge tube The so that outputs a laser beam added.

  The gas laser oscillation apparatus, laser welding apparatus, and gas laser processing apparatus using the gas laser oscillation method of the present invention include a plurality of excitation gases obtained by mixing carbon dioxide gas, nitrogen, and helium gas at different mixing ratios, two or more discharge tubes, A rear mirror, a half mirror, a laser beam excitation power source, an oscillation trigger unit of the laser beam excitation power source, and a laser beam excitation control unit, and an excitation gas having a different mixing ratio is put into the two or more discharge tubes, The discharge tubes are arranged in series between the rear mirror and the half mirror, which are opposed to each other by a resonator length (L), with the longitudinal axis aligned, and the laser light excitation control means performs the laser light excitation. Controlling the oscillation trigger means of the power source and the laser beam excitation power source to oscillate the laser beam in the discharge tube between the rear mirror and the half mirror; It is configured to output a laser beam plus laser beam waveform produced serial by each of the discharge tube. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
First, the first embodiment will be described. FIG. 1 shows a configuration diagram of a gas laser oscillation apparatus according to Embodiment 1 of the present invention. In FIG. 1, the first discharge tube 10 and the second discharge tube 20 are arranged in series between the rear mirror 1 and the half mirror 2 which are opposed to each other by a predetermined resonator length (L), and the longitudinal axes thereof coincide with each other. It is arranged. Each discharge tube 10, 20 has gas inlets 10 a, 20 a at one end and gas outlets 10 b, 20 b at the other end, and the gas inlets 10 a, 20 a are connected to the first excitation gas cylinder 13 and the second excitation gas cylinder 23, respectively. is doing.

  The first discharge tube 10 is charged with a first excitation gas for producing a laser beam having a flat waveform from the first excitation gas cylinder 13, and the second discharge tube 20 is supplied with a spire pulse from the second excitation gas cylinder 23. A second excitation gas for producing a laser beam having a waveform is inserted.

  In the present invention, the excitation gas is disposable, and when the first excitation gas and the second excitation gas of the first discharge tube 10 and the second discharge tube 20 become old, each discharge tube 10, Each of the 20 gas outlets 10b and 20b is discharged to the outside air.

  A first pulse power supply 11 and a second pulse power supply 21 are connected to the first discharge tube 10 and the second discharge tube 20, respectively. The laser light excitation control means is omitted in FIG. 1, but the first and second discharges are controlled by controlling the oscillation trigger means 12 and 22 of the first and second pulse power supplies 11 and 21. The tubes 10 and 20 are discharged.

As already described, in an axially excited short pulse carbon dioxide laser device, an excitation gas in which carbon dioxide, nitrogen gas, and helium gas are mixed as a laser medium is enclosed in a discharge tube made of an insulator such as glass. ing. A main electrode is provided in the discharge tube, and a main power source is connected to these main electrodes so that a discharge is generated in the discharge tube. Fast electrons generated by this discharge, excites the N ₂ molecules raised to a high energy level, the excited N ₂ molecules, excited by energizing the CO ₂ molecule collides with the CO ₂ molecule , Raise the energy level. At that time, the energy level of the N ₂ molecule decreases. The inversion-distributed CO ₂ molecules are amplified in the resonator by a rear mirror (total reflection mirror) and a half mirror (partial reflection mirror) arranged so as to face both ends of the discharge tube, and stimulated emission of laser light is performed. A laser beam is output to the outside. This principle is the same in the gas laser oscillation apparatus of the present invention.

  In the gas laser oscillation apparatus of the present invention, first, the first discharge tube 10 is discharged by the oscillation trigger means 12 of the first pulse power supply 11. Further, the second discharge tube 20 is discharged by the oscillation trigger means 22 of the second pulse power source 21. Then, the laser beam is amplified between the rear mirror 1 and the half mirror 2 which are opposed to each other by a predetermined resonator length (L), stimulated emission is performed, and the laser light is output from the half mirror 2 to the outside. .

  That is, both the first discharge tube 10 and the second discharge tube 20 are made of glass tubes, and there are discharge electrodes at the ends, but they are windows (windows) 10c and 20c through which laser light passes. The laser light penetrates the first discharge tube 10 and the second discharge tube 20 from the rear mirror 1 and hits the half mirror 2 and is reflected by the half mirror 2 to be reflected by the second discharge tube 20 and the first discharge tube 10. , Hits the rear mirror 1 and is reflected and amplified by the rear mirror 1.

  By the way, the laser light penetrates the first discharge tube 10 and the second discharge tube 20 from the rear mirror 1 and hits the half mirror 2 and is reflected by the half mirror 2, and the second discharge tube 20 and the first discharge tube. The structure of repeatedly passing through 10 and hitting the rear mirror 1 and reflecting by the rear mirror 1 is similar to that in FIG. In the configuration of FIG. 20, an excitation gas having a single mixing ratio is commonly used for a plurality of discharge tubes, but in the present invention, an excitation gas having a different mixing ratio is used for each discharge tube.

  Thus, when passing through the first discharge tube 10, a flat waveform (first time waveform, W 1) is added to the laser light by the first discharge tube 10, and the second discharge tube 20 A pulse-like waveform (second time waveform, W2) is added to the laser light. Since the flat waveform by the first discharge tube 10 is long and the spire pulse-like waveform by the second discharge tube 20 is short, the spire pulse-like waveform is added where the laser light output has a flat waveform. It becomes a waveform.

  FIGS. 2A and 2B show a flat waveform in the first discharge tube 10 by discharging the first discharge tube 10 in the gas laser oscillation apparatus according to the first embodiment of the present invention shown in FIG. Next, the second discharge tube 20 is discharged by the oscillation trigger means 22 of the second pulse power source 21 so that a spire pulse-like waveform is formed in the second discharge tube 20, and a predetermined resonator length ( L) A waveform of the laser beam output from the half mirror 2 is shown by being amplified between the rear mirror 1 and the half mirror 2 which are opposed to each other by being separated and stimulated emission of the laser beam.

  FIG. 2A shows an output waveform (PW1) having a flat waveform and having a spire pulse-like waveform added at the latter half of the timing. FIG. 2 (b) shows an output waveform (PW2) having a flat waveform and having a spire pulse-like waveform added at the first half timing. A flat waveform can be obtained by arbitrarily setting the timing at which the first discharge tube 10 and the second discharge tube 20 are discharged by the oscillation trigger means 12 and 22 of the first and second pulse power supplies 11 and 21, respectively. On the other hand, it is possible to adjust at which timing the waveform of the spire pulse shape is added.

FIG. 3A schematically shows the mixing ratio of the first excitation gas placed in the first discharge tube 10 of the gas laser oscillation apparatus according to Embodiment 1 of the present invention. The mixing ratio of the gas composition referred to as “long pulse” is, for example, CO ₂ : N ₂ : He = 1: 3: 4 in volume ratio. The longer N ₂ is, the higher the gas pressure is (the longer the discharge time is), the longer the pulse and the flat laser beam 50 are emitted. FIG. 3B shows a waveform (first time waveform, W1-1) measured when the mixing ratio of the gas composition is, for example, CO ₂ : N ₂ : He = 1: 3: 4 in volume ratio. Shown as an example. In FIG. 3B, the horizontal axis is the time axis (t) and one scale is 20 μsec. The vertical axis represents the laser intensity (w) with 1 scale being 1 kw. Incidentally, the pulse energy (shaded part) at this time was 50 mJ (millijoule).

FIG. 4A is a diagram schematically showing the mixing ratio of the second excitation gas put in the second discharge tube 20 of the gas laser oscillation apparatus according to Embodiment 1 of the present invention. The second discharge tube 20 contains carbon dioxide gas, nitrogen, and helium as a second excitation gas in a volume ratio of CO ₂ : N ₂ : He = 20: 1: 5 to 40. The applicant has invented the creation of a spire-like waveform without a tail with this mixing ratio, and has already been disclosed in JP-A-2014-107349. Please refer to this publication if necessary.

FIG. 4B shows a waveform (second time waveform, W2-1) measured when the mixing ratio of the gas composition is CO ₂ : N ₂ : He = 20: 1: 5 to 40 in volume ratio. ) As an example. In FIG. 4B, in order to make the waveform easier to see, the horizontal axis is the time axis (t), and one scale is 1 μsec, unlike FIG. 3B. The vertical axis represents the laser intensity (w) with one scale being 10 kw. Incidentally, the pulse energy (shaded part) at this time was 10 mJ (millijoule).

  5 and 6 are waveforms (waveforms PW1-1 and PW2-1) of laser light output from the gas laser oscillation apparatus according to Embodiment 1 of the present invention. FIG. 5 corresponds to the waveform shown in FIG. FIG. 6 corresponds to the waveform shown in FIG. Changing the timing of the oscillation trigger 22 changes where the laser light having a spire pulse shape is added to the laser light having a flat waveform.

  When the preheating time is lengthened by laser welding, a plurality of waveforms are added as shown in FIG. 5, and when the preheating time is shortened, a plurality of waveforms are added as shown in FIG.

  In addition, what was demonstrated using FIGS. 3-6 is an example of Embodiment 1 of this invention, and if the excitation gas of another mixing ratio is used, the laser output of the waveform which combined the other waveform is possible. .

  Hereinafter, a case where laser welding is performed with the laser beam 50 output from the gas laser oscillation device 60 according to the first embodiment of the present invention in which two discharge tubes 10 and 20 are arranged in series will be described with reference to FIG.

  The gas laser oscillator 60 according to the first embodiment of the present invention is obtained by finishing the basic configuration shown in FIG. 1 as an apparatus. FIG. 7 shows a part of a nozzle that is an output port of the laser light 50. The positional relationship between the gas laser oscillation device 60 and the object to be welded will be described.

  7A to 7D, a laser light-absorbing resin material 81 that absorbs the laser light 50 in a color such as opaque or black is placed on a pedestal (not shown), and a transparent laser light is placed thereon. The laser beam transmitting resin material 80 that passes through is overlapped, and both of the welding objects are laser welded. In addition, the figure of the left side of FIG. 7 has shown the positional relationship of the cross section of a welding target object, and a laser beam. The diagram on the right side of FIG. 7 shows the laser beam irradiation timing when performing the process of the diagram on the left side.

In FIG. 7A, the gas laser oscillation device 60 irradiates the surface of the laser light absorbing synthetic resin material 81 with a laser beam 50 having a flat waveform and preheats (hereinafter referred to as “preheating” for short). the start _{(t 11} time). In FIG. 7 (b), a larger preheating portion 82 continues to preheating _{(t 12} time). In FIG. 7 (c), by irradiating a laser beam 50 which has a high energy spire pulsed waveform, once to melt portion 83 of the preheating section 82 (t ₁₃ time). Then, in FIG. 7D, after heating with the laser beam 50 having a flat waveform (at time t ₁₄ ), the laser beam is cooled and solidified, and the laser beam-absorbing synthetic resin material 81 and the laser beam are transmitted through the welded portion 84. The welded synthetic resin material 80 is welded, and the laser welding is finished.

  In FIG. 7, the waveform of the laser light is changed to an output waveform (waveform PW1) that finally appears after a flat waveform starts and then a spire pulse-like waveform comes again and becomes a flat waveform. Therefore, preheating is performed to cause the laser light absorbing resin material 81 to generate heat, and the contact surfaces of the laser light absorbing resin material 81 and the laser light transmitting resin material 80 are softened and brought into close contact with each other. Is rapidly heated and melted with a spire pulse waveform. This realizes laser welding quickly and reliably to obtain a predetermined welding strength.

  Next, with reference to FIG. 8, a description will be given of a case where a hole is formed in the laser light-absorbing resin material with the laser light output from the gas laser oscillation apparatus according to the first embodiment of the present invention.

  8 (a) to 8 (d), a laser light absorbing resin material 81 that absorbs laser light in a colored color such as opaque or black, which is an object to be processed, is placed on a perforated base (not shown). 50 shows a step of making a hole by applying 50. In addition, the figure on the left side of FIG. 8 shows the positional relationship between the cross section of the workpiece and the laser beam. The diagram on the right side of FIG. 8 shows the laser beam irradiation timing when the process of the diagram on the left side is performed.

In FIG. 8 (a), the gas laser oscillator 60 starts preheating by irradiation of laser beam 50 which has a flat waveform toward the laser-absorbing synthetic resin material 81 surface (t ₂₁ time). In FIG. 8 (b), by irradiating a laser beam 50 which has a high energy spire pulsed waveform, the preheat portion 82-1 to the molten portion 83-1 (t ₂₂ time). In FIG. 8 (c), the a hole 85 _{(t 23} time). Then, in FIG. 8 (d), the gas laser oscillator 60 is heated by the laser beam 50 in which the flat waveform (t ₂₄ time), cooled, and finished the drilling solidified.

  When piercing a laser light-absorbing resin material or glass material by irradiating a laser beam, the peripheral part of the range that becomes the hole is not yet heated, It is desirable to instantaneously heat and melt the laser light-absorbing resin material or glass material in the range. Therefore, in the steps of FIGS. 8A to 8D, immediately after the preheating starts, a laser beam having a high-energy spire pulse-like waveform is irradiated to make a hole at once.

  As described above, the present invention does not use the laser beam having the output waveform generated by the spire pulse and the tail as in the prior art, but adds a plurality of waveforms, specifically, a flat waveform and a spire pulse-like waveform. The laser beam is output, and the laser beam is used for laser welding of synthetic resin materials, drilling of synthetic resin materials and glass materials, groove engraving, and other laser processing.

  In addition, by adjusting the excitation timing of each discharge tube within the same timing and the rest of the timing, the laser beam with a plurality of waveforms can be output and laser welding suitable for the welding target or processing target And laser processing.

(Embodiment 2)
Next, Embodiment 2 will be described. In the gas laser oscillation apparatus of Embodiment 2 of the present invention, three discharge tubes, first, second, and third discharge tubes 10, 20, and 30 are arranged in series.

  FIG. 9 is a configuration diagram of the gas laser oscillation apparatus according to the second embodiment. Between the left rear mirror 1 and the right half mirror 2 in FIG. 9, the first discharge tube 10, the second discharge tube 20, and the third discharge tube 30 are aligned in a straight line with their longitudinal axes aligned. is there. The rear mirror 1 on the left side and the half mirror 2 on the right side are opposed to each other with an interval of a predetermined resonator length. Then, on the line connecting the centers of the reflection surfaces of the rear mirror 1 and the half mirror 2, the axial centers of the three discharge tubes from the first discharge tube 10 to the third discharge tube 30 are aligned.

  Each discharge tube 10, 20, 30 is formed with gas inlets 10 a, 20 a, 30 a at one end and gas outlets 10 b, 20 b, 30 b at the other end. The gas inlets 10 a, 20 a, 30 a are respectively connected to the first excited gas cylinder. 13, the connection to the second excitation gas cylinder 23 and the third excitation gas cylinder 33 is the same as the configuration of the first embodiment shown in FIG.

The first discharge tube 10 is filled with a first excitation gas (for example, a gas having a mixing ratio of CO ₂ : N ₂ : He = 1: 3: 4). The third discharge tube 30 is filled with a second excitation gas (for example, gas having a mixing ratio of CO ₂ : N ₂ : He = 20: 1: 5 to 40). The three discharge tubes from the first discharge tube 10 to the third discharge tube 30 have first to third pulse power sources 11, 21, 31 and trigger means 12 for the first to third pulse power sources, 22 and 32 are attached.

  The laser light excitation control means is omitted in FIG. 9, but the first to third oscillation trigger means 12, 22, and 32 of the pulse power supplies 11, 21, and 31 are controlled to start from the first. The third discharge tubes 10, 20, and 30 are discharged.

  In the first discharge tube 10, the first pulse power supply 11 is started up and discharged by the trigger means 12 of the first pulse power supply 11 to add a flat waveform to the laser light 50. In the second discharge tube 20 and the third discharge tube 30, the pulse power sources 21 and 31 are started up and discharged by the trigger means 22 and 32 of the pulse power source, and a spire pulse-like waveform is added to the laser light 50. I am doing so.

  In the gas laser oscillation apparatus according to the second embodiment of the present invention, the first discharge tube 10 to the third discharge tube 30 are discharged almost simultaneously, and a waveform generated by each discharge tube is added to the laser light 50. .

FIGS. 10A to 10C show timings at which the respective waveforms are generated in the first discharge tube 10 to the third discharge tube 30. In FIG. 10A, a flat waveform is added to the laser beam 50 at the timing (t ₃₁ ). In FIGS. 10B and 10C, the waveform of each spire pulse is added to the laser beam 50. In the first discharge tube 10, the discharge starts at the timing (t ₃₁ ) and in the second discharge tube 20 and the third discharge tube 30 at the timing (t ₃₂ ). Then, it is amplified between the rear mirror 1 and the half mirror 2, and is stimulated and emitted as a laser beam 50 to which the waveforms generated by the respective discharge tubes of the first discharge tube 10 to the third discharge tube 30 are added. Light is being output.

  That is, in FIG. 10 (d), one waveform is obtained by adding the respective waveforms generated by the respective discharge tubes 10, 20, and 30 to the laser beam 50.

In FIG. 10 (d), the laser beam 50 is a waveform obtained by adding one flat waveform and two spire pulse-like waveforms. In the waveform of FIG. 10 (d), the laser beam is raised in a flat waveform and preheated, and then two spire pulse waveforms are added at the same time for rapid heating, and then the flat waveform is heated. The laser beam irradiation is finished. In FIG. 10, since the second discharge tube 20 and the third discharge tube 30 are discharged at the same timing (t ₃₂ ), two spire pulse-shaped waveforms overlap each other. Therefore, the two spire pulse-like waveforms are added to the laser light waveform as a two-fold height waveform obtained by superimposing the height of one spire pulse-like waveform.

  The laser beam irradiation method that rapidly heats up the height of a plurality of spire pulse-shaped waveforms after preheating in this way is effective for drilling thick synthetic resin, for example. Is done.

In FIG. 11, the timing of discharging the second discharge tube 20 and the third discharge tube 30 is earlier than the timing (t ₄₁ ) at which the first discharge tube 10 generates a flat waveform. shows the situation when the discharged simultaneously t _42). When comparing FIG. 10 and FIG. 11, after a flat waveform is generated in the first discharge tube 10, the height of one spire pulse-shaped waveform is doubled at an arbitrary timing. It can be easily understood that the waveform can be rapidly heated in addition to the waveform of the laser beam.

(Embodiment 3)
A third embodiment will be described. In the gas laser oscillation device of Embodiment 3 of the present invention, the four discharge tubes 10, 20, 30, and 40 are arranged in series.

  FIG. 12 is a configuration diagram of the gas laser oscillation apparatus according to the third embodiment. A first discharge tube 10, a second discharge tube 20, a third discharge tube 30, and a fourth discharge tube 40 are arranged in a straight line between the left rear mirror 1 and the right half mirror 2 in FIG. . The rear mirror 1 on the left side and the half mirror 2 on the right side are opposed to each other with an interval of a predetermined resonator length. Then, on the line connecting the centers of the reflection surfaces of the rear mirror 1 and the half mirror 2, the axes of the four discharge tubes from the first discharge tube 10 to the fourth discharge tube 40 are aligned and aligned.

  Each discharge tube 10, 20, 30, 40 has a gas inlet 10a, 20a, 30a, 40a at one end and a gas outlet 10b, 20b, 30b, 40b at the other end, and the gas inlets 10a, 20a, 30a, 40a. Are connected to the first excitation gas cylinder 13, the second excitation gas cylinder 23, the third excitation gas cylinder 33, and the fourth excitation gas cylinder 43, respectively, as in the configuration of the first embodiment shown in FIG. It is.

The first discharge tube 10 and the third discharge tube 30 are filled with a first excitation gas (for example, a gas having a mixing ratio of CO ₂ : N ₂ : He = 1: 3: 4), The second discharge tube 20 and the fourth discharge tube 40 are filled with a second excitation gas (for example, a gas having a mixing ratio of CO ₂ : N ₂ : He = 20: 1: 5 to 40). Yes. The four discharge tubes from the first discharge tube 10 to the fourth discharge tube 40 have first to fourth pulse power sources 11, 21, 31, 41 and trigger means for the first to fourth pulse power sources, respectively. 12, 22, 32 and 42 are attached.

  The laser light excitation control means is omitted in FIG. 12, but the oscillation trigger means 12, 22, 32, 42 of the first to fourth pulse power supplies 11, 21, 31, 41 are controlled. The first to fourth discharge tubes 10, 20, 30, 40 are discharged.

  In the first discharge tube 10 and the third discharge tube 30, when the pulse power supplies 11 and 31 are started up and discharged by the trigger means 12 and 32 of the pulse power supply, a flat waveform of the laser beam is generated. ing. In the second discharge tube 20 and the fourth discharge tube 40, when the pulse power sources 21 and 41 are started up and discharged by the trigger means 22 and 42 of the pulse power source, a spire pulse-like waveform of the laser light is generated. I am doing so.

  In the gas laser oscillation apparatus of Embodiment 3 of the present invention, each of the first discharge tube 10 to the fourth discharge tube 40 is discharged at a predetermined timing, and the laser beam has a waveform generated by each discharge tube. ing.

FIGS. 13A to 13E show at which timing the first discharge tube 10 to the fourth discharge tube 40 generate the respective waveforms. In the first discharge tube 10 shown in FIG. 13A and the third discharge tube 30 shown in FIG. 13C, the laser intensity is different, but a flat waveform is generated in the laser light. In the second discharge tube 20 shown in FIG. 13B and the fourth discharge tube 40 shown in FIG. 13D, the peak laser intensity and the pulse rising timing are different, but the waveform of a spire pulse is added to the laser light. Is caused. The first discharge tube 10 has a timing (t ₅₁ ), the second discharge tube 20 has a timing (t ₅₂ ), the third discharge tube 30 has a timing (t ₅₂ ), and the fourth discharge tube 40 has a timing (t ₅₂ ). The discharge starts at the timing (t ₅₃ ).

  The laser light is amplified between the rear mirror 1 and the half mirror 2 and has a waveform generated by each discharge tube from the first discharge tube 10 to the fourth discharge tube 40.

  That is, in FIG. 13E, a single waveform is obtained by adding each waveform generated by each discharge tube to the laser light.

  In FIG. 13 (e), an output waveform is obtained by adding two flat waveforms and two spire pulse waveforms to the laser beam. In the waveform of FIG. 13 (e), the laser beam is started up in a flat waveform and preheated, then rapidly heated in the first spire pulse waveform, and once in the flat waveform, Rapid heating is performed with the second spire pulse-like waveform, and finally the flat waveform is heated to finish the laser beam irradiation.

  The laser beam irradiation method in which the preheating is repeated in this manner and the rapid heating of the spire pulse in a plurality of stages is effective for, for example, a drilling operation having a relatively large diameter.

  FIG. 14 shows the appearance of a gas laser drilling apparatus for drilling in a dome-shaped glass container 87. The gas laser oscillation device 90 of the present invention is attached to the tip of the robot arm 100, and as described from the gas laser oscillation device 90, a laser beam having a waveform obtained by adding a plurality of waveforms is attached to the holding jig 110 and fixed. The glass container 87 is irradiated.

  FIG. 15 shows an enlarged cross-sectional view after making a hole 88 in the dome-shaped glass container 87.

  In the description of the gas laser oscillators of the first to third embodiments, the laser beam excitation control unit supplies the laser beam excitation power to at least two of the discharge tubes at the same timing and the remaining timing is different. The case has been described in which the laser beam is oscillated in the discharge tube between the reflecting mirror and the semi-reflecting mirror and the laser beam in which the waveform of the laser beam generated by each discharge tube is superimposed is output.

  However, according to the gas laser oscillation method of the present invention, when a plurality of waveforms formed by a plurality of discharge tubes are added to the output waveform, the plurality of waveforms can be added at a timing. Due to the practical need for laser welding and laser processing, it may be more convenient that the plurality of waveforms do not overlap and are separated in terms of timing. The gas laser oscillation method of the present invention can be used in the form of a preferable output waveform according to practical needs.

  The gas laser oscillation method of the present invention can be applied to a gas laser oscillation apparatus using this method, a laser welding apparatus for a synthetic resin material, a gas laser processing apparatus for drilling or engraving a groove in a synthetic resin material or glass material, and a semiconductor manufacturing equipment The present invention can be applied to industrial gas laser processing apparatuses and dental gas laser processing apparatuses.

1: Rear mirror 2: Half mirror 10: First discharge tube 10a: Gas inlet of first discharge tube 10b: Gas outlet of first discharge tube 10c: Window of first discharge tube 11: First pulse power source 12: Oscillation trigger means of the first pulse power supply 13: First excitation gas cylinder 20: Second discharge tube 20a: Gas inlet of the second discharge tube 20b: Gas outlet of the second discharge tube 20c: Second Window of discharge tube 21: Second pulse power supply 22: Oscillation trigger means of second pulse power supply 23: Second excitation gas cylinder 30: Third discharge tube 40: Fourth discharge tube 50: Laser light 60, 90 : Gas laser oscillation device 70, 71: Gas storage container 80: Laser light transmitting resin material 81: Laser light absorbing resin material 82: Preheating part 83: Melting part 84: Welding part 85, 88: Hole 8 7: Glass container L: Resonator length

Claims (9)

A plurality of excitation gases in which carbon dioxide, nitrogen, and helium gas are mixed at different mixing ratios;
Two or more discharge tubes,
A total reflector,
A semi-reflector,
A laser beam excitation power source;
An oscillation trigger means of a laser beam excitation power supply;
Laser light excitation control means,
Put the excitation gas of different mixing ratio into the two or more discharge tubes,
Arranging the discharge tubes in series between the total reflection mirror and the semi-reflection mirror,
The laser light excitation control means controls the laser light excitation power source and the oscillation trigger means of the laser light excitation power source to oscillate laser light in the discharge tube between the total reflection mirror and the semi-reflection mirror,
Configured to output a laser beam to which the waveform of the laser beam generated by each of the discharge tubes is added,
A gas laser oscillation device characterized by the above.   As the plurality of excitation gases, a first excitation gas in which carbon dioxide gas, nitrogen, and helium gas are mixed in a mixing ratio that makes the laser light waveform flat, and a carbon dioxide gas and nitrogen in a mixing ratio that makes the laser light waveform a spire pulse. The gas laser oscillation apparatus according to claim 1, comprising a second excitation gas mixed with helium gas.   3. The laser light waveform is a spire pulse in which the mixing ratio of carbon dioxide gas, nitrogen, and helium gas is a volume ratio of 20: 1: 5 to 40 as the second excitation gas. Gas laser oscillation device.   A laser welding apparatus configured to weld an object to be welded using the gas laser oscillation apparatus according to claim 1.   A laser processing apparatus configured to process an object to be processed using the gas laser oscillation apparatus according to claim 1.   A laser processing apparatus configured to form a hole, a groove, or a recess in a workpiece using the gas laser oscillation apparatus according to claim 1. A plurality of excitation gases in which carbon dioxide, nitrogen, and helium gas are mixed at different mixing ratios;
Two or more discharge tubes,
A total reflector,
A semi-reflector,
A laser beam excitation power source;
An oscillation trigger means of a laser beam excitation power supply;
Using laser light excitation control means,
Put the excitation gas of different mixing ratio into the two or more discharge tubes,
Arranging the discharge tubes in series between the total reflection mirror and the semi-reflection mirror,
The laser light excitation control means controls the laser light excitation power supply and the oscillation trigger means of the laser light excitation power supply,
A laser beam is oscillated in the discharge tube between the total reflection mirror and the semi-reflection mirror,
The laser beam added with the waveform of the laser beam generated by each discharge tube is output.
A gas laser oscillation method characterized by the above.   As the plurality of excitation gases, a first excitation gas in which carbon dioxide gas, nitrogen, and helium gas are mixed in a mixing ratio that makes the laser light waveform flat, and a carbon dioxide gas and nitrogen in a mixing ratio that makes the laser light waveform a spire pulse. The gas laser oscillation method according to claim 7, wherein a second excitation gas mixed with helium gas is used.   As the second excitation gas, a mixture ratio of carbon dioxide gas, nitrogen and helium gas in a volume ratio of 20: 1: 5 to 40 is used, and a waveform obtained by adding a spire pulse waveform to a laser beam waveform The gas laser oscillation method according to claim 8, which is configured as follows.

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