JP7121383B2 - Gas laser oscillation method, and gas laser oscillation device, laser welding device, and laser processing device using this method - Google Patents

Description

The present invention relates to a gas laser oscillation method, and a gas laser oscillation device, a laser welding device, and a laser processing device using this method. , a gas laser oscillation method for oscillating laser light having a third output waveform that is a combination of both output waveforms, and a gas laser oscillation apparatus, laser welding apparatus, and laser processing apparatus using this method. More specifically, based on a flat first output waveform and a pulsed second output waveform of laser light, a gas laser oscillation method for oscillating laser light with a third output waveform that is a combination of both output waveforms; and a gas laser oscillation device, a laser welding device, and a laser processing device using this method.

In a conventional axial excitation short-pulse carbon dioxide laser device, an excitation medium gas (laser gas, hereinafter abbreviated as " The discharge tube is provided with main electrodes, and a main power supply is connected to the main electrodes to generate discharge in the discharge tube. The high-speed electrons generated by this discharge excite the _N2 molecules to a high energy level, and the excited _N2 molecules collide with the _CO2 molecules to give energy to the _CO2 molecules and excite them. , raises the energy level. At that time, the energy level of the _N2 molecule is lowered. The reversed distribution of CO ₂ molecules is amplified in the cavity by a rear mirror (total reflection mirror) and a half mirror (partial reflection mirror) placed facing each other at both ends of the discharge tube, causing stimulated emission of laser light, and the half mirror laser light is output to the outside (see Patent Document 1, for example).

FIG. 16 shows an output waveform of laser light output from a conventional axially pumped short-pulse carbon dioxide gas laser device. In FIG. 16, the vertical axis represents the laser intensity (W) and the horizontal axis represents time, showing the output waveform of the laser light. When the output of laser light is started, the laser intensity in FIG. 16 rises sharply from point O (time t1) to point P as a steeple pulse, and then decreases. The state of decrease is that after the laser intensity once decreases to point Q (time t2), which is less than half of point P, which is the peak of the steeple pulse, the laser intensity gradually decreases so as to draw a pulse tail. , to point S (time t3) where the laser intensity is zero. A shape connecting points O, P, Q, and S in FIG. 16 is a general output waveform of laser light.

On the other hand, as a method of industrially using laser light, laser welding is performed by irradiating a plurality of laminated synthetic resin materials with laser light, and laser light is irradiated to synthetic resin materials to form holes. .

For example, when laser welding synthetic resin materials, as shown in FIG. A laser beam 50 is irradiated from above the resin material 80 .

The laser light 50 is absorbed by the laser light absorbing resin material 81, and the laser light absorbing resin material 81 is melted to form a melted portion 83 inside. The surface 83a of the melted portion 83 melts with the facing surface 80a of the laser light transmitting resin material 80 facing and abutting thereon.

However, as shown in FIG. 17 emphasizing the irregularities on the surfaces of the laser light transmitting resin material 80 and the laser light absorbing resin material 81, the laser light transmitting resin material 80 and the laser light absorbing resin material 81 each When the degree of adhesion is weak, such as when the surface roughness is rough or there is warpage, and a gap is formed between the facing surface 80a and the surface 83a described above, the facing surface 80a and the surface 83a are in close contact with each other. It takes time to melt into each other. Even if the facing surface 80a and the surface 83a are in close contact with each other, the adhesive force of light contact may not allow quick and reliable welding, resulting in insufficient welding strength after the welding operation.

Therefore, conventionally, when performing laser welding of synthetic resin materials, the range to be welded between the laser light transmitting resin material 80 and the laser light absorbing resin material 81 is heated by heater heating, electromagnetic induction heating, hot air heating, infrared lamp heating, or the like. After the laser light transmitting resin material 80 and the laser light absorbing resin material 81 are brought into close contact with each other, the resin material 80 and the laser light absorbing resin material 81 are preheated and softened by means of . It has been proposed to obtain (see, for example, Patent Document 2).

That is, as shown in FIG. 18(a), preheating is performed by another heat source before laser light irradiation (time points 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 area to be welded between the laser light transmitting resin material 80 and the laser light absorbing resin material 81 is softened by preheating. and adhere to it. When the laser beam 50 is irradiated, the laser beam absorbing resin material 81 is melted while being in close contact with each other. 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 of the laser beam 50 is stopped, they are cooled, solidified and welded. As shown in FIG. 18(a), preheating enables rapid and reliable laser welding.

Here, preheating is not required if laser light having a waveform as shown in FIG. 18A, that is, a waveform as shown by the dotted line in FIG. 18B can be irradiated. An apparatus having only one laser light output means, which is not provided with other preheating means, can perform rapid and reliable laser welding or other various laser processing.

However, in the conventional gas laser oscillator, before the normal laser beam waveform (waveform in the form of a line connecting points O, P, Q, and S) as shown in FIG. Adding an optical output waveform was difficult.

For example, in a conventional gas laser oscillator, as shown in FIG. 19, a single discharge tube (laser tube) is provided with a plurality of discharge areas D1, D2, . It was applied with a target or an appropriate phase difference. Thus, a pulse shaping method for a pulsed laser is known, in which laser oscillation is performed in each discharge region to arbitrarily shape the waveform of the output pulse of the laser (see Patent Document 3).

However, since one type of excitation gas is allowed to flow through one discharge tube, laser light with one type of waveform is output. In the apparatus of FIG. 19, the discharge timings of a pair of adjacent electrodes C (C1 to C5) and electrodes A (A1 to A5) are shifted to form a laser beam waveform. It was difficult to do as indicated by the dotted line in

Also, as shown in FIG. 20, a gas laser oscillator is known in which a plurality of discharge tubes for flowing the same excitation gas are arranged between a total reflecting mirror and a semi-reflecting mirror (partially passing mirror). A plurality of discharged discharge tubes output laser light having one type of waveform. Although it is possible to increase or decrease the output intensity of the laser light by varying the output of the laser light by combining the on/off of the discharge for each of the plurality of discharge tubes, the waveform of the laser light is shown by the dotted line in FIG. 18(b). Thus, the waveform of the laser light was not created arbitrarily (see Patent Document 4).

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

The present invention provides a gas laser oscillation method for oscillating laser light having a third output waveform, which is a combination of both output waveforms, based on a first output waveform and a second output waveform of laser light, and a method using this method. An object of the present invention is 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 laser light having a third output waveform that is a combination of the first flat output waveform and the second pulse-shaped output waveform of the laser light, 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 laser light having a third output waveform that is a combination of the first output waveform and the second output waveform of the laser light. An object of the present invention is to provide a gas laser oscillation method, and a gas laser oscillation device, a laser welding device, and a laser processing device using this method.

In order to achieve the above object, in the gas laser oscillator according to the present invention, a first excitation gas is introduced between a rear mirror and a half mirror facing each other with a predetermined resonator length (L). and a second discharge tube containing a second excitation gas are arranged in series, the first discharge tube is discharged using the oscillation trigger means of the first pulse power supply, and the second discharge tube It is configured to discharge using the oscillation trigger means of the pulse power source to generate a laser beam with a flat waveform and a steeple-shaped pulse waveform.

By arbitrarily setting the timing of operating the oscillation triggering means of the second pulse power supply of the second discharge tube with respect to the timing of operating the oscillation triggering means of the first pulse power supply of the first discharge tube, flat It is configured so that the position of the steeple-shaped pulse waveform added to the normal waveform can be set arbitrarily.

In the gas laser oscillator according to the present invention, a first excitation gas, such as carbon dioxide, nitrogen, and helium, mixed in a volume ratio of 1:3:4 is introduced into the first discharge tube. A flat waveform is formed, and a second excitation gas such as carbon dioxide, nitrogen, and helium is mixed at a volume ratio of 20:1:5 to 40 as a second excitation gas in the second discharge tube. to create a steeple pulse-like waveform.

Between a rear mirror (total reflection mirror) 1 and a half mirror (semi-reflection mirror) 2 facing each other with a cavity length (L), a first discharge tube containing a first excitation gas and a second A second discharge tube containing two excitation gases is arranged in series, and amplified through the first discharge tube and the second discharge tube between the rear mirror 1 and the half mirror 2 to produce a flat waveform and a steeple pulse shape. A laser beam with a waveform added with a waveform is output.

When laser welding is performed by the gas laser oscillator according to the present invention, for example, the contact surface of the object to be welded is preheated by irradiating the contact surface of the object to be welded with the laser beam of the flat waveform portion, and then the waveform is formed into a steeple pulse shape. It is also possible to strongly irradiate the contact surface of the object to be welded with the laser beam to melt it, and then irradiate the object to be welded with the laser beam of the flat wave portion to heat the object, thereby welding the object to be welded.

Further, when a hole is made in a synthetic resin material or a glass material by the gas laser oscillator according to the present invention, for example, the object to be processed is preheated by irradiating the laser beam of the flat wave portion to a certain extent, and then the object is immediately pierced in the shape of a steeple pulse. The wavy laser beam strongly irradiates the workpiece to make a hole, and then the flat wavy laser beam irradiates the workpiece to heat it, causing the workpiece to scatter and sag after drilling. It is also possible to suppress the degree of occurrence of such as.

Further, in the gas laser oscillator according to the present invention, three or more discharge tubes are arranged in series between the rear mirror and the half mirror, each discharge tube is filled with a dedicated excitation gas, and each discharge tube is used to produce a laser beam. It allows you to add waveforms that This enables the gas laser oscillator 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 waveform laser beam in which a flat waveform and a steeple pulse waveform are added, and which has a flat laser output portion before the steeple pulse, or before and after the steeple pulse. there is

In particular, the present invention makes it possible to provide a new gas laser oscillation method using multiple excitation gases.

Further, the present invention makes it possible to provide a gas laser oscillator that generates a waveform laser beam having flat laser output portions before, or before and after, a steeple pulse by using this gas laser oscillation method.

The present invention also provides a laser welding device for synthetic resin materials, and a gas laser processing device for punching holes in synthetic resin materials, glass materials, and glass blocks and forming grooves and recesses using this gas laser oscillation device. make it possible to

1 is a configuration diagram of a gas laser oscillator according to Embodiment 1 of the present invention; FIG. (a) and (b) output waveforms of laser light output from the gas laser oscillator according to the first embodiment of the present invention. (a) A diagram schematically showing an example of the mixing ratio of the first excitation gas put into the first discharge tube of the gas laser oscillation device according to the first embodiment of the present invention, (b) The figure which measured and showed the waveform of the laser beam produced by one excitation gas. (a) A diagram schematically showing an example of the mixing ratio of the second excitation gas put into the second discharge tube of the gas laser oscillation device according to the first embodiment of the present invention, (b) the second excitation gas shown in (a) FIG. 4 is a diagram showing measured waveforms of laser light generated by two excitation gases; FIG. 4 is a diagram showing waveforms of laser light to which waveforms of the first and second discharge tubes are added in the gas laser oscillator according to the first embodiment of the present invention; FIG. 4 is a diagram showing waveforms of laser light to which waveforms of the first and second discharge tubes are added in the gas laser oscillator according to the first embodiment of the present invention; (a) to (d) Using the gas laser oscillation device according to the first embodiment of the present invention, the cross section of the process of overlapping and laser-welding the laser light transmitting resin material and the laser light absorbing resin material and the output timing of the laser light. Figures shown in pairs. (a) to (d) are diagrams showing a pair of a cross section of a process of drilling a laser light absorbing resin material and output timing of laser light using the gas laser oscillation device according to the first embodiment of the present invention. . The block diagram of the gas laser oscillation apparatus concerning Embodiment 2 of this invention. (a) A diagram showing the waveform of laser light produced by the first discharge tube according to Embodiment 2 of the present invention, (b) The waveform of laser light produced by the second discharge tube according to Embodiment 2 of the present invention. (c) Waveform of laser light produced by the third discharge tube according to Embodiment 2 of the present invention, (d) From the first discharge tube to the third discharge tube according to Embodiment 2 of the present invention The figure which showed the output waveform of the laser beam formed by adding a waveform. (a) Diagram showing the waveform of laser light produced by the first discharge tube according to the modification of the second embodiment of the present invention, (b) In the second discharge tube according to the modification of the second embodiment of the present invention Waveform of laser light produced, (c) Diagram showing waveform of laser light produced by the third discharge tube according to the modification of the second embodiment of the present invention, (d) According to the modification of the second embodiment of the present invention The figure which showed the output waveform of the laser beam which added 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) A diagram showing the waveform of laser light produced by the first discharge tube according to Embodiment 3 of the present invention, (b) The waveform of laser light produced by the second discharge tube according to Embodiment 3 of the present invention. (c) Waveform of laser light produced by the third discharge tube according to Embodiment 3 of the present invention, (d) Waveform of laser light produced by the fourth discharge tube according to Embodiment 3 of the present invention, (e) A diagram showing output waveforms of laser light obtained by adding waveforms of the first to fourth discharge tubes. The figure which showed the state during the drilling process of the gas laser processing apparatus which perforates the glass material concerning Embodiment 4 of this invention. FIG. 11 is an enlarged cross-sectional view of glass drilled by a gas laser processing apparatus for drilling a glass material according to a fourth embodiment of the present invention; The figure which showed an example of the waveform of the pulse of the conventional laser beam. FIG. 10 is a view showing a state in which a laser beam transmitting resin material and a laser beam absorbing resin material are overlapped and laser welded by a conventional laser welding method; (a) A diagram schematically showing a portion to which preheating energy is applied to a conventional laser beam pulse waveform, (b) A laser beam pulse waveform showing a portion to which preheating energy is applied in (a). A diagram showing the waveform when incorporated into the dotted line. FIG. 2 is a configuration diagram of another conventional gas laser oscillator. FIG. 2 is a configuration diagram of still another conventional gas laser oscillator.

The gas laser oscillation method of the present invention includes a plurality of excitation gases in which carbon dioxide gas, nitrogen gas and helium gas are mixed at different mixing ratios, two or more discharge tubes, a rear mirror (total reflection mirror), and a half mirror (semi-reflection mirror). , a laser light excitation power supply, an oscillation triggering means for the laser light excitation power supply, and a laser light excitation control means, and pumping gases of different mixing ratios are put into the two or more discharge tubes, and a predetermined cavity length (L) Between the rear mirror and the half mirror facing apart, the discharge tubes are arranged in series with their longitudinal axes aligned, and the laser light excitation control means controls the laser light excitation power source and the laser light excitation power source. By controlling the oscillation trigger means, the discharge tube between the rear mirror and the half mirror oscillates the laser light, and the laser light to which the waveform of the laser light generated by each of the discharge tubes is added is output. there is

The gas laser oscillation device, the laser welding device, and the gas laser processing device using the gas laser oscillation method of the present invention include a plurality of excitation gases obtained by mixing carbon dioxide gas, nitrogen gas, and helium gas at different mixing ratios, and two or more discharge tubes. , a rear mirror, a half mirror, a laser light excitation power source, oscillation trigger means for the laser light excitation power source, and laser light excitation control means; Between the rear mirror and the half mirror facing each other with a cavity length (L), the discharge tubes are arranged in series with their longitudinal axes aligned, and the laser light excitation control means controls the laser light excitation. By controlling the oscillation trigger means of the power source and the laser light excitation power source, the discharge tube between the rear mirror and the half mirror oscillates laser light, and the waveform of the laser light generated by each of the discharge tubes is added to the laser. It is configured to emit light. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings.

(Embodiment 1)
First, Embodiment 1 will be described. FIG. 1 shows a block diagram of a gas laser oscillation device according to Embodiment 1 of the present invention. In FIG. 1, a first discharge tube 10 and a second discharge tube 20 are connected in series between a rear mirror 1 and a half mirror 2 facing each other with a predetermined resonator length (L), and the longitudinal axes of the first discharge tube 10 and the second discharge tube 20 are aligned. Let it be placed. Each discharge tube 10, 20 has a gas inlet 10a, 20a at one end and a gas outlet 10b, 20b at the other end. The gas inlets 10a, 20a are connected to a first excitation gas cylinder 13 and a second excitation gas cylinder 23, respectively. is doing.

In the first discharge tube 10, a first excitation gas that produces a flat waveform laser beam is put from a first excitation gas cylinder 13, and in the second discharge tube 20, a steeple pulse is supplied from a second excitation gas cylinder 23. A second excitation gas is introduced that produces a laser beam with a wavy shape.

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, Gas outlets 10b and 20b of 20 are respectively exhausted to the outside air.

A first pulse power source 11 and a second pulse power source 21 are connected to the first discharge tube 10 and the second discharge tube 20, respectively. Although not shown in FIG. 1, the laser light excitation control means controls the oscillation trigger means 12, 22 of the first and second pulse power sources 11, 21 to generate the first and second discharges. The tubes 10, 20 are being discharged.

As already explained, in the axial excitation short-pulse carbon dioxide laser device, an excitation gas, which is a mixture of carbon dioxide gas, nitrogen gas, and helium gas, is sealed as a laser medium in a discharge tube made of an insulating material such as glass. ing. The discharge tube is provided with main electrodes, and a main power supply is connected to the main electrodes to generate discharge in the discharge tube. The high-speed electrons generated by this discharge excite the _N2 molecules to a high energy level, and the excited _N2 molecules collide with the _CO2 molecules to give energy to the _CO2 molecules and excite them. , raises the energy level. At that time, the energy level of the _N2 molecule is lowered. The reversed distribution of CO ₂ molecules is amplified in the cavity by a rear mirror (total reflection mirror) and a half mirror (partial reflection mirror) placed facing each other at both ends of the discharge tube, causing stimulated emission of laser light, and the half mirror output laser light to the outside. This principle also applies to the gas laser oscillator of the present invention.

In the gas laser oscillator of the present invention, first, the first discharge tube 10 is caused to discharge by the oscillation trigger means 12 of the first pulse power source 11 . Also, the second discharge tube 20 is discharged by the oscillation trigger means 22 of the second pulse power supply 21 . Then, the laser light is amplified between the rear mirror 1 and the half mirror 2 facing each other with a predetermined cavity length (L) apart, stimulated emission of the laser light, 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 a glass tube, and although there are discharge electrodes at the ends, they are windows 10c and 20c through which the laser light passes. , the laser light passes through the first discharge tube 10 and the second discharge tube 20 from the rear mirror 1, hits the half mirror 2, is reflected by the half mirror 2, and is reflected by the second discharge tube 20 and the first discharge tube 10. , hits the rear mirror 1, is reflected by the rear mirror 1, and is amplified.

Incidentally, the laser light passes through the first discharge tube 10 and the second discharge tube 20 from the rear mirror 1, hits the half mirror 2, is reflected by the half mirror 2, and is reflected by the second discharge tube 20 and the first discharge tube. The structure in which the light passes through 10, strikes the rear mirror 1, and is reflected by the rear mirror 1, is repeated, and is similar to that shown in FIG. In the configuration of FIG. 20, one mixture ratio of excitation gas is commonly used for a plurality of discharge tubes, but in the present invention, different mixture ratios of excitation gas are used for each discharge tube.

As a result, when passing through the first discharge tube 10, the first discharge tube 10 adds a flat waveform (first time waveform, W1) to the laser light, and the second discharge tube 20 adds a spire to the laser light. A pulsed waveform (second time waveform, W2) is added to the laser light. Since the flat waveform of the first discharge tube 10 is long and the peak pulse waveform of the second discharge tube 20 is short, the peak pulse waveform is added to the flat waveform of the laser light output. become a waveform.

2(a) and 2(b) show, in the gas laser oscillator according to the first embodiment of the present invention shown in FIG. Then, the second discharge tube 20 is discharged by the oscillation trigger means 22 of the second pulse power supply 21 so that the second discharge tube 20 produces a spire pulse waveform, and the predetermined resonator length ( L) shows the waveform of the laser light output from the half mirror 2, which is amplified between the rear mirror 1 and the half mirror 2 facing each other with a distance of L), and stimulated emission of the laser light.

FIG. 2(a) shows an output waveform (PW1) having a flat waveform and adding a steeple pulse waveform at the latter half of the timing. FIG. 2(b) shows an output waveform (PW2) with a flat waveform and a steeple pulse waveform added in the first half of the timing. By arbitrarily setting the timing of discharging the first discharge tube 10 and the second discharge tube 20 by the oscillation trigger means 12, 22 of the first and second pulse power sources 11, 21, respectively, a flat waveform can be obtained. , it is possible to adjust the timing at which the spire pulse waveform is added.

FIG. 3(a) schematically shows the mixing ratio of the first excitation gas put into the first discharge tube 10 of the gas laser oscillator according to the first embodiment 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 terms of volume ratio. The more N ₂ and the higher the gas pressure (the longer the discharge time), the longer the pulse and the flatter the laser light 50 is emitted. FIG. 3(b) shows a waveform (first time waveform, W1-1) actually measured when the mixing ratio of the gas composition is, for example, CO ₂ :N ₂ :He=1:3:4 by volume. 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 one scale being 1 kw. Incidentally, the pulse energy (hatched portion) at this time was 50 mJ (millijoules).

FIG. 4(a) is a diagram schematically showing the mixing ratio of the second excitation gas put into the second discharge tube 20 of the gas laser oscillator according to the first embodiment of the present invention. The second discharge tube 20 contains carbon dioxide, nitrogen and helium as a second excitation gas in a volume ratio of CO ₂ :N ₂ :He=20:1:5-40. The applicant invented the creation of a steeple pulse waveform with no tail at this mixing ratio, and has already disclosed it in Japanese Patent Application Laid-Open No. 2014-107349. Please refer to the publication if necessary.

FIG. 4(b) shows waveforms ( _second time waveform, _W2-1 ) is shown as an example. In FIG. 4(b), unlike FIG. 3(b), the horizontal axis is the time axis (t) and one scale is 1 .mu.sec in order to make the waveform easier to see. The vertical axis represents the laser intensity (w), with one scale being 10 kw. Incidentally, the pulse energy (hatched portion) at this time was 10 mJ (millijoules).

5 and 6 show waveforms (waveforms PW1-1 and PW2-1) of laser light output from the gas laser oscillator according to the first embodiment of the present invention. FIG. 5 corresponds to the waveforms previously shown in FIG. 2(a). FIG. 6 corresponds to the waveform previously shown in FIG. 2(b). When the timing of the oscillation trigger 22 is changed, where in the laser light with a flat waveform the laser light with a steeple pulse waveform is added changes.

When the preheating time is lengthened in 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.

It should be noted that what has been described with reference to FIGS. 3 to 6 is an example of Embodiment 1 of the present invention, and if an excitation gas with a different mixture ratio is used, a laser output with a waveform combining other waveforms is possible. .

A case of laser welding with a laser beam 50 output from a gas laser oscillator 60 according to Embodiment 1 of the present invention in which two discharge tubes 10 and 20 are arranged in series will be described below 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, and FIG. The positional relationship between the gas laser oscillator 60 and the object to be welded will be explained.

7A to 7D, an opaque or colored, such as black, laser light absorbing resin material 81 that absorbs the laser light 50 is placed on a pedestal (not shown), and a transparent laser light absorbing resin material 81 is placed thereon. It shows a process of superimposing a laser beam transmitting resin material 80 that transmits laser light and laser welding the two objects to be welded. Note that the diagram on the left side of FIG. 7 shows the positional relationship between the section of the object to be welded and the laser beam. The diagram on the right side of FIG. 7 shows the timing of laser light irradiation during the process of the diagram on the left side.

In FIG. 7A, the gas laser oscillator 60 preheats the surface of the laser light-absorbing synthetic resin material 81 by irradiating it with a laser beam 50 having a flat waveform (hereinafter abbreviated as "preheating"). is started (at time _t11 ). In FIG. 7(b), preheating is continued to enlarge the preheated portion 82 (time _t12 ). In FIG. 7(c), the preheated portion 82 is melted 83 at once by irradiating a laser beam 50 having a high-energy steeple pulse waveform ₍ time t13). Then, in FIG. 7(d), after heating with a flat wave-shaped laser beam 50 ₍ at time t14), the laser beam absorbing synthetic resin material 81 and the laser beam transmitting material 81 at the welded portion 84 are cooled and solidified. The synthetic resin material 80 is welded to complete the laser welding.

In FIG. 7, the waveform of the laser light is an output waveform (waveform PW1) in which a flat waveform starts, a spire pulse-shaped waveform appears, becomes a flat waveform again, and finally disappears. Therefore, the laser light absorbing resin material 81 is preheated to generate heat, the contact surfaces of the laser light absorbing resin material 81 and the laser light transmitting resin material 80 are softened, and the contact surfaces are brought into close contact with each other. is rapidly heated and melted in a steeple pulse-like waveform at once. As a result, laser welding can be performed quickly and reliably, and a predetermined welding strength can be obtained.

Next, with reference to FIG. 8, the case where the laser light emitted from the gas laser oscillator according to the first embodiment of the present invention is used to form a hole in the laser light-absorbing resin material will be described.

In FIGS. 8A to 8D, a laser light-absorbing resin material 81, which is an object to be processed and is colored such as opaque or black and absorbs laser light, is placed on a perforated pedestal (not shown). 50 is applied and the process of making a hole is shown. Note that the diagram on the left side of FIG. 8 shows the positional relationship between the cross section of the object to be processed and the laser beam. The diagram on the right side of FIG. 8 shows the timing of laser light irradiation during the process of the diagram on the left side.

In FIG. 8A, the gas laser oscillator 60 irradiates the surface of the laser light absorbing synthetic resin material 81 with a flat wavy laser light 50 to start preheating (time _t21 ). In FIG. 8(b), the preheated portion 82-1 is turned into the melted portion 83-1 by irradiating the laser beam 50 having a high-energy steeple pulse waveform ₍ time t22). In FIG. 8(c), a hole 85 is made (time _t23 ). Then, in FIG. 8(d), the gas laser oscillator 60 is heated by the flat-wavy laser beam 50 (time _t24 ), cooled, and solidified to complete drilling.

When irradiating a laser beam to make a hole in a laser light-absorbing resin material or glass material, the peripheral portion of the area where the hole will be formed has not yet been heated, and while it has a certain strength at a low temperature, the hole should be removed. It is desirable to instantaneously heat and melt the laser light-absorbing resin material or the glass material within the range of . Therefore, in the steps of FIGS. 8A to 8D, a high-energy steeple pulse-shaped laser beam is irradiated immediately after the preheating is started to open the hole at once.

As described above, the present invention does not use the laser light with the output waveform composed of the spire pulse and the tail as it is as in the conventional art, but adds a plurality of waveforms, specifically, a flat waveform and a spire pulse waveform. The laser beam is output, and the laser beam is used to perform laser welding of synthetic resin materials, drilling and grooving of synthetic resin materials and glass materials, and other laser processing.

In addition, by adjusting the excitation timing of each discharge tube so that some are the same and others are different, laser light with multiple waveforms is output to achieve laser welding suitable for the object to be welded or the object to be processed. and laser processing.

(Embodiment 2)
Next, Embodiment 2 will be described. In the gas laser oscillator according to 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 a gas laser oscillator according to a second embodiment. A first discharge tube 10, a second discharge tube 20, and a third discharge tube 30 are aligned in a straight line between the left rear mirror 1 and the right half mirror 2 in FIG. be. The left rear mirror 1 and the right half mirror 2 have their reflecting surfaces opposed to each other with a predetermined cavity length therebetween. Three discharge tubes, the first discharge tube 10 to the third discharge tube 30, are aligned on a line connecting the centers of the reflecting surfaces of the rear mirror 1 and the half mirror 2 with their axial centers aligned.

Each discharge tube 10, 20, 30 is formed with a gas inlet 10a, 20a, 30a at one end and a gas outlet 10b, 20b, 30b at the other end. 13, a second excitation gas cylinder 23, and a third excitation gas cylinder 33 are connected to each other, which 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 with 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, a mixture 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 are respectively provided with first to third pulse power sources 11, 21 and 31, trigger means 12 for the first to third pulse power sources, 22 and 32 are installed.

9, the laser light excitation control means controls the oscillation trigger means 12, 22, 32 of the first to third pulse power sources 11, 21, 31, The third discharge tubes 10, 20, 30 are discharged.

Then, in the first discharge tube 10, the first pulse power source 11 is activated, and the trigger means 12 of the first pulse power source 11 discharges the laser light 50 so as to add a flat waveform. Further, in the second discharge tube 20 and the third discharge tube 30, the pulse power sources 21 and 31 are activated and discharged by the trigger means 22 and 32 of the pulse power sources to add a steeple pulse waveform to the laser light 50. I'm trying

In the gas laser oscillator according to Embodiment 2 of the present invention, the first discharge tube 10 to the third discharge tube 30 are discharged almost simultaneously, and the waveforms generated by each discharge tube are added to the laser light 50. .

FIGS. 10A to 10C show timings for generating respective waveforms in the first discharge tube 10 to the third discharge tube 30. FIG. In FIG. 10(a), a flat waveform is added to the laser light 50 at timing ( _t31 ). In FIGS. 10(b) and 10(c), the laser light 50 is added with respective steeple pulse waveforms. The first discharge tube 10 starts discharging at the timing (t ₃₁ ), and the second discharge tube 20 and the third discharge tube 30 start discharging at the timing (t ₃₂ ). Then, it is amplified between the rear mirror 1 and the half mirror 2, and stimulatedly emitted as laser light 50 to which the waveforms generated by the first discharge tube 10 to the third discharge tube 30 are added. emits light.

That is, in FIG. 10(d), the laser light 50 is combined with the waveforms generated by the discharge tubes 10, 20, and 30 to form one waveform.

In FIG. 10(d), the laser beam 50 has a waveform in which one flat waveform and two steeple pulse waveforms are added. In the waveform of FIG. 10(d), the laser light rises in a flat waveform and preheats, then two steeple pulse waveforms are added simultaneously to perform rapid heating, and then flat waveform heating is performed. , the laser beam irradiation is completed. In FIG. 10, since the second discharge tube 20 and the third discharge tube 30 are discharged at the same timing ( _t32 ), two steeple pulse waveforms overlap. Therefore, the two steeple pulse-shaped waveforms are added to the waveform of the laser light as a double height waveform obtained by overlapping the height of one steeple pulse-shaped waveform.

After preheating in this way, the method of irradiating a laser beam with rapid heating to a height obtained by stacking a plurality of steeple pulse-shaped waveforms is effective, for example, for drilling a thick synthetic resin. be done.

Note that FIG. 11 shows that the timing of discharging the second discharge tube 20 and the third discharge tube 30 is the timing (t ₄₁ ) at which the flat waveform is generated in the first discharge tube 10, and the earlier timing ( t ₄₂ ), the situation is shown when they are discharged at the same time. 10 and 11, after a flat waveform is generated in the first discharge tube 10, the height of one steeple pulse waveform is doubled at an arbitrary timing. It is easily understood that rapid heating can be performed in addition to the waveform of the laser light as the waveform of .

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

FIG. 12 is a configuration diagram of a gas laser oscillator according to a 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 left rear mirror 1 and the right half mirror 2 have their reflecting surfaces opposed to each other with a predetermined cavity length therebetween. Four discharge tubes from the first discharge tube 10 to the fourth discharge tube 40 are arranged on a line connecting the centers of the reflecting surfaces of the rear mirror 1 and the half mirror 2 with their axial centers 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. 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, which is the same as the configuration of Embodiment 1 shown in FIG. is.

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

Although the laser light excitation control means is omitted in FIG. , 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 sources 11 and 31 are activated and the trigger means 12 and 32 of the pulse power sources discharge, a flat waveform of laser light is generated. ing. Further, in the second discharge tube 20 and the fourth discharge tube 40, when the pulse power sources 21 and 41 are activated and the trigger means 22 and 42 of the pulse power sources discharge, a steeple pulse waveform of the laser light is generated. I'm trying

In the gas laser oscillator according to 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 so that the laser light has a waveform generated by each discharge tube. ing.

FIGS. 13(a) to 13(e) show at what timing the first discharge tube 10 to the fourth discharge tube 40 generate respective waveforms. The first discharge tube 10 shown in FIG. 13(a) and the third discharge tube 30 shown in FIG. 13(c) have different laser intensities, but produce a flat waveform in the laser light. The second discharge tube 20 shown in FIG. 13B and the fourth discharge tube 40 shown in FIG. is causing Timing (t 51 ) for the first discharge tube 10, timing (t ₅₂ ) for the second discharge tube 20, timing (t ₅₂ ) for the third discharge tube 30, and timing (t ₅₂ ) for the fourth discharge tube 40 , discharge starts at timing (t ₅₃ ).

The laser light is amplified between the rear mirror 1 and the half mirror 2 and adds waveforms generated by the first to fourth discharge tubes 10 to 40 .

In other words, in FIG. 13(e), the laser light is combined with each waveform generated by each discharge tube to form one waveform.

In FIG. 13(e), an output waveform is obtained by adding two flat waveforms and two steeple pulse waveforms to the laser light. In the waveform of FIG. 13( e ), the laser light rises with a flat waveform for preheating, then rapidly heats with the first spire pulse waveform, then heats with a flat waveform once, and then heats with a flat waveform. Rapid heating is performed with a steeple pulse-shaped waveform for the second time, and finally, flat waveform heating is performed to complete the laser beam irradiation.

A method of irradiating a laser beam that repeats such preheating and then rapid heating in a plurality of steps in the shape of a spire pulse is effective, for example, for drilling a hole having a relatively large diameter.

FIG. 14 shows the appearance of a gas laser drilling device for drilling a dome-shaped glass container 87 . A gas laser oscillating device 90 of the present invention is attached to the tip of a robot arm 100, and a dome-shaped laser beam having a plurality of waveforms added from the gas laser oscillating device 90 is attached and fixed to a holding jig 110 as already described. A glass container 87 is irradiated.

FIG. 15 shows an enlarged cross-sectional view of the dome-shaped glass container 87 after the holes 88 are formed.

In the description of the gas laser oscillators of Embodiments 1 to 3 above, the laser excitation control means supplies the laser excitation power to at least two of the discharge tubes at the same timing for some and different timings for the rest. A case has been described in which laser light is oscillated in the discharge tube between the reflecting mirror and the semi-reflecting mirror, and the waveform of the laser light generated by each discharge tube is superimposed to output the laser light.

However, according to the gas laser oscillation method of the present invention, when adding a plurality of waveforms generated by a plurality of discharge tubes to the output waveform, the plurality of waveforms can be added at different timings. Due to the practical needs of laser welding or laser machining, it may be advantageous for the waveforms to be non-overlapping and separated in timing. The gas lasing method of the present invention can be used with a preferred form of 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 synthetic resin materials, a gas laser processing apparatus for drilling holes or grooves in synthetic resin materials or glass materials, and semiconductor manufacturing equipment. industrial gas laser processing equipment and dental gas laser processing equipment.

Reference Signs List 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 supply 12: Oscillation trigger means of first pulse power supply 13: First excitation gas cylinder 20: Second discharge tube 20a: Gas inlet of second discharge tube 20b: Gas outlet of second discharge tube 20c: Second discharge tube Window of discharge tube 21: second pulse power supply 22: oscillation trigger means for second pulse power supply 23: second excitation gas cylinder 30: third discharge tube 40: fourth discharge tube 50: laser light 60, 90 : Gas laser oscillator 70, 71: Gas 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 87: Glass container L: resonator length

Claims (9)

The first excitation gas is a mixture of carbon dioxide gas, nitrogen, and helium gas at a mixing ratio that makes the laser beam waveform flat, and the second excitation gas is a mixture of carbon dioxide gas, nitrogen, and helium gas at a mixture ratio that makes the laser beam waveform a steep pulse. a plurality of excitation gases obtained by mixing carbon dioxide gas, nitrogen gas and helium gas at different mixing ratios, including the excitation gas of
two or more discharge tubes;
a total reflecting mirror;
a semi-reflector;
a laser light excitation power supply;
an oscillation trigger means for a laser light excitation power source;
and laser light excitation control means,
putting the excitation gas in different mixing ratios into the two or more discharge tubes;
arranging the discharge tubes in series between the total reflection mirror and the semi-reflection mirror;
controlling the laser light excitation power supply and the oscillation trigger means of the laser light excitation power supply by the laser light excitation control means to cause the discharge tube between the total reflection mirror and the semi-reflection mirror to oscillate a laser light;
The laser light to which the waveform of the laser light generated by each of the discharge tubes is added is output by adding the waveform of the laser light generated by each of the discharge tubes so as to include the waveform of the spire pulse .
A gas laser oscillator characterized by: controlling the laser light excitation power supply and the oscillation trigger means of the laser light excitation power supply by the laser light excitation control means to cause the discharge tube between the total reflection mirror and the semi-reflection mirror to oscillate a laser light;
2. The waveform of the laser light added with the waveform of the laser light generated by each of the discharge tubes is such that after a flat waveform starts, a steeple pulse-shaped waveform comes and then becomes a flat waveform again. 2. The gas laser oscillation device according to . 2. The second excitation gas is carbon dioxide gas, nitrogen gas, and helium gas in a volume ratio of 20:1:5 to 40, so that the laser light waveform becomes a steeple pulse. Item 3. The gas laser oscillation device according to item 2. 3. A laser welding apparatus configured to weld an object to be welded by using the gas laser oscillator according to claim 1 or claim 2. 3. A laser processing apparatus configured to process an object using the gas laser oscillation apparatus according to claim 1 or 2. 3. A laser processing apparatus configured to form holes, grooves or recesses in an object using the gas laser oscillation apparatus according to claim 1 or 2. The first excitation gas is a mixture of carbon dioxide gas, nitrogen, and helium gas at a mixing ratio that makes the laser beam waveform flat, and the second excitation gas is a mixture of carbon dioxide gas, nitrogen, and helium gas at a mixture ratio that makes the laser beam waveform a steep pulse. a plurality of excitation gases obtained by mixing carbon dioxide gas, nitrogen gas and helium gas at different mixing ratios, including the excitation gas of
two or more discharge tubes;
a total reflecting mirror;
a semi-reflector;
a laser light excitation power supply;
an oscillation trigger means for a laser light excitation power source;
using laser light excitation control means,
putting the excitation gas in different mixing ratios 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,
oscillating a laser beam in the discharge tube between the total reflection mirror and the semi-reflection mirror;
The laser light to which the waveform of the laser light generated by each discharge tube is added is output by adding the waveform of the laser light generated by each of the discharge tubes so as to include the waveform of the spire pulse .
A gas laser oscillation method characterized by: controlling the laser light excitation power supply and the oscillation trigger means of the laser light excitation power supply by the laser light excitation control means to cause the discharge tube between the total reflection mirror and the semi-reflection mirror to oscillate a laser light;
8. The waveform of the laser light added with the waveform of the laser light generated by each of the discharge tubes is such that after a flat waveform starts, a spire pulse-like waveform comes and then becomes a flat waveform again. The gas laser oscillation method described in . 8. The second excitation gas is carbon dioxide gas, nitrogen gas and helium gas in a mixing ratio of 20:1: 5 to 40 by volume, so that the laser light waveform becomes a steeple pulse waveform. Or the gas laser oscillation method according to claim 8 .

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