JPH02126691A - Co2 gas laser controller - Google Patents

Abstract

PURPOSE:To control a high-accuracy, high-response and high-quality compensation regarding all fluctuation causes by a method wherein an output of a specific-time pulse output setting circuit is output only during a period decided by a specific-timing and specific-period setting circuit. CONSTITUTION:A signal voltage which is proportional to a magnitude of that of a relative displacement degree or higher with reference to a regular reference-mode waveform such as a laser output or the like is input to a detection circuit 16; the signal voltage itself is compared with a setting reference voltage or an output which has passed a differential circuit is compared with the setting reference voltage; an output of the detection circuit 16 is input to a specific-timing and specific-period setting circuit 17. The specific-timing and specific-period setting circuit 17 inputs an output VT to a stationary-time pulse output setting circuit 18, a specific-time pulse output setting circuit 19 and a changeover switch circuit 20 only during a specific period T1 after a specific timing TD since the output of the detection circuit 16 has risen. A pulse peak value Pp, a pulse width Pw and a pulse frequency Pf are set at the stationary-time pulse output setting circuit 18; 21, 22, 23 whose waveforms are different are changed over by using a changeover switch 24 and are used as a setting command signal VS 29.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a CO2 gas laser control device, and more particularly to pulse waveform and pulse frequency control of a DC-excited or RF-excited CO2 gas laser.

2. Description of the Related Art Regarding pulse control of conventional DC-excited or RF-excited CO2 gas lasers, pulse peak value, pulse width,
The output was controlled by changing the pulse frequency. Furthermore, when processing the same shape at the same processing speed, pulsed laser processing was more accurate than CW laser processing because melting due to heat conduction was less likely to occur. Particularly when processing a thick plate, CW laser processing creates a large hole at the cutting start position, resulting in poor quality, so pulse laser processing is sometimes performed only at the start or end of the cutting process.

Problems to be Solved by the Invention Factors that vary the accuracy of laser cutting include laser output, laser processing speed, laser gas flow rate or gas pressure, laser assist gas flow rate or gas pressure, table vibration of the laser processing device, and the surface of the workpiece. Alternatively, there may be changes in laser reflected light or laser scattered light on the back surface, temperature on the front or back surface of the workpiece, changes in laser beam mode, etc.

Conventionally, only laser power feedback has tried to compensate for fluctuation factors, and this laser power feedback compensation control feeds back the laser output and power as a setting command signal, which affects the responsiveness of the laser power sensor. However, in the current version, it is several tens of lll5 (about 20 to 3oIfi8)
However, due to the delay in response, sufficient compensation control was not possible.

Regarding other fluctuation factors, for example, the laser processing speed is compensated and controlled so that it reaches the set command speed, and the total gas pressure of the laser gas flow is also compensated and controlled only so that the set gas flow rate and gas pressure are set. Ta.

If you try to perform compensation control with higher precision and higher response, for example, if you try to achieve higher precision and higher response in terms of laser processing speed, the price of the laser equipment itself will increase the number of current equipment. times (1,5~2.
(approximately 6 times), which resulted in a high price and was not practical.

Means for Solving the Problems In order to solve the above-mentioned problems, the CO2 laser control device of the present invention has the following advantages: the discharge voltage generated in the discharge tube, the discharge current flowing in the discharge tube, and the electric power injected into the discharge tube.

Laser output, laser processing speed of a laser processing device that processes using laser output, gas flow rate or gas pressure of laser gas flowing in the discharge tube, and laser assist gas flow rate or gas pressure of the laser processing nozzle.

Table vibration of laser processing equipment, laser reflected light or laser scattered light on the surface of the workpiece or the back surface that has passed through it, the magnitude and instantaneous output ripple of the surface temperature of the workpiece on the front surface of the workpiece or the back surface that has passed through it. a detection circuit that detects at least one of the magnitude of the output of the detection circuit; A specific period is measured from a specific pulse rise timing of the laser pulse output and the rise of the output of the detection circuit. A specific timing specific period setting circuit, a steady pulse output setting circuit that sets the pulse peak value, pulse width, and pulse frequency of the laser pulse output during steady processing, and the output of the specific timing and specific period setting circuit. The output of the specific time pulse setting circuit and the specific timing specific period setting circuit for setting the pulse peak value, pulse width, pulse frequency, and rising slope and falling slope of the pulse output of the laser at the specific time when a changeover switch circuit configured to switch between the output of the steady-time pulse output setting circuit and the specific-time pulse output setting circuit; inputting the output of the detection circuit to the specific timing specific period setting circuit; Inputting the output of the specific timing specific period setting circuit to the steady state pulse output setting circuit, the specific time pulse output setting circuit, and the changeover switch circuit;
The output of the steady state pulse output setting circuit and the output of the specific time pulse output setting circuit are input, and the output of the changeover switch circuit serves as a setting command signal for setting the magnitude of the laser output.

Effect In the above means, instead of faithfully controlling the compensation using a setting command signal that determines the magnitude of the laser output, etc., the compensation control is performed in advance to compensate for fluctuation factors such as the laser output and the fluctuation factors of the laser processing cutting accuracy. Another function that determines the magnitude of the laser output (outputs the pulse waveform and pulse frequency, that is, outputs the output of the pulse output setting circuit at a specific time only for a period determined by the specific period setting circuit at a specific time, or uses a built-in frequency switch) The output of the pulse output setting circuit is input to the pulse waveform conversion circuit, and the output of the pulse waveform conversion circuit is output only for a period determined by the specific timing and period setting circuit, or the output of the pulse output setting circuit during steady state is converted to a pulse waveform. Since the output of the pulse waveform conversion circuit is output only during the period determined by the detection circuit, active compensation control is possible, and high precision and high accuracy can be achieved without increasing the price of the laser device itself.
High-response, high-quality compensation can be controlled for all variable factors. By using the control device of the present invention, compensation control can be performed not only at the starting point at the start of the cutting process and at the end point at the end of the cutting process, but also at the time of the steady cutting process.

In addition, by providing a second pulse peak value that is either higher than the steady pulse peak value or lower than the steady pulse peak value for only the second time period, it is possible to perform precision cutting and at the same time greatly increase the latitude in cutting conditions. spread.

In addition, the detection circuit detects not only the laser output, but also the laser processing speed, the discharge voltage of the discharge tube, the discharge current, the injected discharge power,
It can also be replaced with the detection of laser gas flow rate or gas pressure, laser assist gas flow rate or gas pressure, table vibration, laser reflected light or scattered light, surface temperature of the workpiece, and degree of relative deviation from the regular reference mode waveform. Even in such cases, the control device of the present invention described above can be effectively used in all detection circuits.

In addition, the control device of the present invention is designed to instantly respond and perform compensation control when the fluctuation factor of laser cutting processing accuracy fluctuates, and returns to the original steady setting command signal at a specific timing and after a specific period of compensation control. To provide a stable, reliable, and inexpensive feedback control method and device using a semi-closed loop system, which does not require a control method and device for high precision and high response, and does not cause damping or activation of compensation control. can.

Embodiment FIG. 1 shows the configuration of a general high-speed axial flow type RF excitation oscillator, and FIG. 2 shows a block diagram of the high-frequency output generator 74 shown in FIG. 1.

3 to 6 show setting command signal circuits of the present invention, and FIG. 3 shows a circuit in which a specific time pulse output setting circuit is added to the conventional steady state pulse output setting circuit for switching.
The figure shows a conventional steady-state pulse output setting circuit with a built-in frequency switching circuit and a pulse waveform conversion circuit that can be switched. Figure 6 shows a conventional steady-state pulse output setting circuit and a pulse waveform. It consists of a conversion circuit and is configured to switch. FIG. 6 is a timing chart of output waveforms of each circuit in FIGS. 3 to 6. FIG. FIG. 7 shows various setting command signals obtained from the waveform conversion circuits of FIGS. 4 and 6. FIG. 8 shows two types of setting command signals having a second peak value obtained from the steady state pulse output setting circuit.

To explain the configuration of the general high-speed axial flow type RF excitation oscillator shown in FIG.
are placed closely together. Parallel plate electrodes 72 and 73 have outputs from a high frequency power source 74, for example 1a, 5a MH
Power of z, 2.5 KW, 2~a KV is supplied. A discharge 75 is generated in the discharge space within the discharge tube element 1 as indicated by the arrow.

A mirror (total reflection mirror) 76 and an output mirror (partial reflection mirror) 77, which are fixedly arranged at both ends of the discharge tube 71, constitute an optical resonator, and a laser output cuff 8 is taken out from the output mirror 7. The laser gas 79 is circulating in the air pipe 8o, and the laser gas 79 whose temperature has been increased by a blower 81 that circulates the emitted electrons 6 and the laser gas 79 is cooled by a heat exchanger 82.

The configuration of the general high-speed axial DC excitation oscillator shown in FIG. 1(b) will be described. Electrodes 92 are provided at both ends of a discharge tube 91 made of a dielectric material such as glass. The electrode 92 is connected to the output of a DC high voltage power supply 93, for example, DC28KV.
, an output of about 1 COmA is supplied. A discharge 94 occurs in the discharge space within the discharge tube 91 sandwiched between the electrodes 92 in the direction shown by the arrow. The mirrors 96 fixedly arranged at both ends of the discharge space and the output mirrors 96 form an optical resonator, and a laser output 97 is extracted from the output mirrors 96.

Laser gas 98 is circulating in air pipe 99 , and laser gas 98 whose temperature has risen due to discharge 94 and blower 1 CO that circulates laser gas 98 is cooled by heat exchanger 101 .

To explain Figure 2, RF that generates high frequency output
The output of the power supply 2 is transmitted via a coaxial cable 3 to a matching box 4 for matching with a load. The output of the matching box 4 is supplied to coupling capacitors 6 to 8 provided to balance parallel loads, and the coupling capacitors 6 to 8 are connected to discharge tubes 9 to 12.
is connected, and the discharge current of the discharge tubes 9 to 12 is transferred to the current transformer CT1.
Detected at 3.

The output of the current transformer c'r13 is input to the detection circuit 14 and compared with the set reference voltage, the output of the detection circuit 14 is input to the setting command signal circuit 16, and the output of the setting command signal circuit 16 is It is input to the RF power supply 2 and changes the setting command within the RF power supply 2. Further, the detection circuit 14 may include a differentiating circuit for detecting the magnitude of output ripple due to instantaneous fluctuations, and the output of this differentiating circuit may be compared with a set reference voltage. Further, in FIG. 2, the output of the current transformer c'r13 for detecting the discharge current is input to the detection circuit 14, but the output of a power monitor or the like for detecting the magnitude of the laser output may be input.

To explain FIG. 3, the FIG. 3 detection circuit 16 is connected to the second
This detection circuit 16 is the same as that of 14 in the figure, and this detection circuit 16 is used to detect the laser output, laser processing speed, discharge voltage generated in the discharge tube, discharge current flowing in the discharge tube as shown in FIG. power injected into the discharge tube, gas flow rate or gas pressure of the laser gas flowing in the discharge tube, laser assist gas flow rate or gas pressure, table vibration of the laser processing equipment, laser reflected light or laser scattered light on the front or back surface of the workpiece, A signal voltage proportional to the surface temperature of the front or back surface of the workpiece and the degree of relative deviation from the normal reference mode waveform of the laser beam is input, and as explained in Fig. 2 above, the signal voltage itself is The set reference voltage is compared or the output after passing through a differentiator circuit is compared with the set reference voltage, and the output of the detection circuit 16 is input to a specific timing specific period setting circuit 17.

The specific timing specific period setting circuit 1 outputs the output at a specific timing T after the output of the detection circuit 16 rises for one specific period. and is input to the changeover switch circuit 2o.

In the steady state pulse output setting circuit 18, the pulse peak value Pp
, pulse width Pw, and pulse frequency Pf are set, and the waveforms are different (1)21, (2)22.

(3) 23 is switched by the changeover switch 24, '/s2
It becomes 9.

For example, if we correspond to Fig. 8, (1) 21 is shown in Fig. 8 (a).
.

(2) 22 is shown in Figure 8 (C), (3) 23 is shown in Figure 8 (
8) etc.

In addition, in the specific time pulse output setting circuit 19, the pulse peak value Pp, pulse width Pw', and pulse frequency Pc are set similarly to the steady state pulse output setting circuit 18, but the values are different from the values in the normal state, and Here, the pulse rising slope Prt and the pulse falling slope Pft are also set, and those whose waveforms are different are (1)25, (2)26,
(3) 27 is switched by the selector switch 28, and V! l'
It will be 30. The changeover switch 20 is this v529 and VS'
30 and set the setting command signal Vs, V531,
During normal operation, the signal is vs29, but when the output of the specific timing specific period setting circuit rises, VB'30 becomes the setting command signal.

To explain FIG. 4, the detection circuit 16 and the specific timing specific period setting circuit 17 in FIG. 4 are the same as those in FIG. 3, and the output of the specific timing specific period setting circuit in FIG. The signal is input to an output setting circuit 32 and a pulse waveform conversion circuit 33. The steady state pulse frequency setting circuit that sets the steady state pulse frequency, the steady state Pf34, and the specific time Pf'35 are switched by the changeover switch 36, and the waveform that sets the pulse peak value Pp and pulse width P is changed. Different (1) 37° (2) 3
B , (3) is input to 39, (1) 37 , (
2) 3s.

(3) 39 is switched by the changeover switch 4o, and its output is input to the pulse waveform conversion circuit 33.

In the waveform conversion circuit 41, pulse peak value Pp, pulse II
FW', pulse rising slope Prt *Pulse falling slope Pft is set, and is composed of a voltage dividing circuit, a one-jit timer circuit, a slope circuit, etc.

At a specific timing and at the rising edge of the output of the specific period setting circuit 33, the specific Pf' 35 and the waveform conversion circuit 41 are selected by the changeover switches 36 and 42, and the setting command signal VB,
Vs'45 is switched to v544. Steady P during steady state
(34 is selected, and the setting command signal vs, vs'45 is v
It is s43.

In contrast to FIG. 3, FIG. 4 shows that a pulse output setting circuit 32 with a built-in frequency switching circuit is used in a specific time pulse output setting circuit 19.
The pulse peak value Pp and pulse width P are shared, and the specific Pf'35 is one type, and the output thereof is received by the pulse waveform conversion circuit 33, and the pulse peak value pp, pulse IMPw, and pulse rising slope Prt are , the pulse falling slope Pft are created and set, and can be constructed at low cost using another embodiment shown in FIG. On the other hand, FIG. 6 is another implementation plan of FIG. 3, which does not have the specific timing and specific period setting circuit 17 compared to FIG. It can be set using the conversion circuit 33.

The explanatory numbers in FIG. 5 are the same as those in FIGS. 3 and 4. However, in the case of FIG. 5, as mentioned above, the specific Pf'36 cannot be set, so the output of the waveform conversion circuit 41 is V5'69, and the setting command signal is vs.

”/, '46.

When FIG. 6 is explained in correspondence with FIGS. 3 to 6, FIG. 6(a) V and g are VS29 in FIG. 3 and '1B4a in FIG. 4.

This corresponds to VS29 in FIG.

FIG. 6(k)) Vn is an example of the output of the detection circuit 16, where the output is VD for a time TvD47, and (C) Vt is the output of the specific timing and specific period setting circuit 17 at that time. An example of the output shows a case where the output V is output for a specific period of time T148, and (f') TD
When the specific timing TO is set as shown in 53, the specific time becomes TI'70.

In FIG. 6(d), the specific timing TD53 of 0 is set to zero, and the same output as the steady state pulse output setting circuit is set during the specific period T148. This example shows the output of the detection circuit 16 in FIG. At the rise of vD, the steady state pulse is postponed and started, and the subsequent pulses have a steady state pulse frequency of Pf49 as shown in (d). Dross adheres to the cutting surface and the reflected light It is conceivable to apply this to the case where the next pulse is immediately postponed and removed when the pulse returns to the discharge tube via a mirror and is expanded.In this case, the detector 16 uses a laser reflected light. Alternatively, a signal voltage proportional to the magnitude of the scattered light is input.

In addition, in (6), the specific timing 'rDsa in (f) is zero, but during the specific period T148 in (c), the pulse rising slope, Pr upper 6o, and pulse frequency Pf'61 are realized in Fig. 3 or 4. This can be applied when the laser processing speed exceeds the set value even momentarily. In this case, after the specific time T148 has elapsed, the pulse frequency is returned to the normal pulse frequency P1'52 and the pulse waveform as shown in (e).

On the other hand, (0) may be applied when masking is performed using laser output, or when the focal point approaches the processing surface due to table vibration such as an impact on the laser processing table, and then the focal point moves away from the processing surface.

In addition, (G') is the case realized in Fig. 5 (specific timing TD53 of 0, specific period T of (C), and the case where there is no 48 and the pulse frequency is Pf58 at steady state as shown in q). show.

Note that Prt of (0 Pf' 64 , PrB6 , ρ)
Reference numeral 67 indicates the pulse frequency at the specific time and the steady state mentioned above, and the pulse rising slope at the specific time.

To explain Fig. 7, Fig. 7 (&) is obtained from the steady state pulse output setting circuit 18 (b) to (f').
is the specific time pulse output setting circuit 19 in Fig. 3 or the fourth
This is obtained from the waveform conversion circuit 41 shown in FIGS.
b) is the pulse peak value PpE59, (C) is the Norms width P, 60, (d) is the pulse rising slope Prt61, (
e) is the pulse falling slope Pft62, (0 is (b),
(C), (d>, and (6) are all set.

To explain FIG. 8, FIG. 8 (&) shows the setting command signal vs29 of the pulse output setting circuit in a steady state, and (b) shows the laser pulse output waveform in that case. In (C), after the first time period T163 from the rise of the pulse output, a second Norkle peak value Pp266 lower than the steady value is provided for a second time period T264, and after the second time period, the original steady pulse peak value is restored. (d) shows the laser pulse output waveform in that case.

Contrary to (C), (6) sets the second pulse peak value Pp26B higher than the steady value to the second pulse peak value Pp26B after the first time period T186.
267 (0 indicates the laser pulse output waveform in that case).

Figures 8 (Q) and (6) are shown in Figures 3 and 6 as mentioned above.
Figures (2) 22, (3) 23, Figure 4 (2L3 a,
(3) It is set in 39, but the second peak value is shown in Figure 4.
It may be created and set by the waveform conversion circuit 41 in FIG. 5 or the like, and may be used as a setting command signal for the pulse output setting circuit at a specific time.

Regarding the effect of providing the second peak value in Figure 8, we considered the effect of providing the second peak value lower than the steady value in the hope that it would be effective for cutting with even higher precision in addition to the effect of the enhanced pulse. The pulse peak value Pp during the first time period is such that the enhanced leading spike edge quickly melts the metal, quickly reduces the high reflectivity of the metal surface, and increases the absorption rate of laser light.

and the pulse peak value Pp2 during the subsequent second time period.
melts at much lower power levels.

The original pulse peak value Pp after the second time period is reliably cut accurately and uniformly, and variations in surface roughness are reduced. The pulse peak value Pp2 during the second time period is as long as there is enough energy to melt the pulse.
Pp is not necessary. This low second peak value can also be applied to welding other than cutting. It can also be applied to cutting plastics, rubber, etc. In addition, for materials with a second peak value higher than the steady value, materials with a large coefficient of thermal expansion,
There is a risk of cracking due to thermal stress. For example, it was designed to be effective in cutting quartz glass, and the problem with cutting quartz glass and other types of glass is that cracks and other fractures occur near the cut surface due to thermal strain. .

The method of providing a second peak value higher than the steady value is considered to be more effective for thicker plates such as quartz glass, and is preheated at the peak value P of the first time period to bring it near the softening point.

Next, cutting is performed at the peak value Pp2 of the second time period, and instead of rapidly removing the energy heat input after the second time period,
- Return to the original peak value Pp. By doing this, cracks and other cracks will not occur, the surface roughness will be reduced, and the cut edges will be rounded, making it possible to omit polishing or puff finishing in the post-process.

It can also be used to cut ceramics, asbestos cement acrylic boards, etc.

Although not all the variable factors input to the detection circuit described above have been explained in the explanation of the drawings above, the control method and apparatus of the present invention can be applied.

In addition, multiple detection circuits are provided, for example, when the laser output and laser processing speed are combined, and when the processing conditions deviate from the appropriate processing conditions,
For example, when the machining speed decreases, it is easy to think of performing power control compensation control using the control method and device of the present application to return to proper conditions, such as by reducing the laser output.

Furthermore, the basic control method and device of the present application can be similarly applied to YAG lasers and other lasers. In addition to cutting, it can also be applied to welding, drilling (scribing, marking, trimming), surface treatment (surface hardening, surface modification), and metals and non-metals.

It can also be used in conjunction with a TIG welder, MIG welder, spot welder, or seam welder with a laser device. In this case, in addition to the detection circuit described above, the detection circuit must be replaced with a circuit that centrally controls the output of the welding machine. Laser output may also be controlled.

In the future, the pulse waveforms of RF-excited CO2 gas laser devices and the like can be easily and precisely controlled, so water head control methods and devices can be realized without any problems and will be useful.

Effects of the Invention As described above, according to the control device of the present invention, compensation control is performed actively and instantaneously using a different pulse waveform and pulse frequency prepared in advance for fluctuation factors in laser cutting processing accuracy, and the laser device itself High precision, high response, and high quality compensation can be controlled for all variable factors without increasing the price. Furthermore, according to the present invention, compensation control can be performed not only at the start of machining and at the end of machining, but also during steady machining. Furthermore, according to the present invention, when there is a fluctuation, it responds instantaneously and returns to the original steady state after compensation control, eliminating the need for high precision, high response, and expensive equipment, and damping and oscillation of compensation control. It is a stable, reliable, and inexpensive semi-closed loop method. Furthermore, by using the second peak value for the steady waveform, more precise processing can be achieved and at the same time the latitude in processing conditions can be expanded.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the configuration of a general high-speed axial flow type RF excitation oscillator, Fig. 2 is a block diagram of its high-frequency output generator, and Fig. 3 shows a pulse output setting circuit in a steady state. A circuit diagram in which an output setting circuit is added and switched. (Figure 4 is a circuit diagram in steady state) (a circuit with a built-in frequency switching circuit in the pulse output setting circuit) and a pulse waveform conversion circuit, which is configured to switch. Figure 6 is a circuit diagram that is configured with a steady state pulse output setting circuit and a pulse waveform conversion circuit, and is configured to switch. Figure 6 is a timing chart of the output waveforms of each circuit in Figures 3 to 5. Figure 7 is a waveform diagram of various setting command signals obtained from the waveform conversion circuits of Figures 4 and 6;
The figure is a waveform diagram of two types of setting command signals having a second peak value obtained from the steady state pulse output setting circuit. 16...detection circuit, 17...specific timing specific period setting circuit, 18...regular pulse output setting circuit, 19...specific time pulse output setting Circuit, 32...Pulse output setting circuit, 33.
...Pulse waveform conversion circuit. Name of agent: Patent attorney Shigetaka Awano and one other person ('
J ζq

Claims (16)

[Claims] (1) In a control device for a DC-excited or RF-excited CO_2 gas laser device, a discharge voltage generated in a discharge tube, a discharge current flowing in the discharge tube, electric power injected into the discharge tube, laser output, and a laser processed using the laser output. Laser processing speed of the processing equipment, gas flow rate or gas pressure of the laser gas flowing in the discharge tube, laser assist gas flow rate or gas pressure of the laser processing nozzle, table vibration of the laser processing equipment, laser on the surface of the workpiece or the back side it has passed through. a detection circuit that detects at least one of reflected light or laser scattered light, the magnitude of the surface temperature of the workpiece on the surface of the workpiece or the back surface through which it has passed, and the magnitude of the instantaneous fluctuation output ripple; A detection circuit that detects the magnitude of the relative deviation from the reference mode waveform of the beam and the magnitude of the instantaneous fluctuation output ripple, and the output of the detection circuit detects the specific pulse rise timing of the laser pulse output and the detection circuit. a specific timing specific period setting circuit that measures a specific period from the rise of the output; a steady pulse output setting circuit that sets the pulse peak value, pulse width, and pulse frequency of the laser pulse output during steady processing; a specific time pulse output setting circuit that sets the pulse peak value, pulse width, pulse frequency, and rising slope and falling slope of the pulse output of the laser at a specific time when the output of the timing specific period setting circuit is output; , a changeover switch circuit to which the output of the specific timing specific period setting circuit is input and switches between the output of the steady state pulse output setting circuit and the specific time pulse output setting circuit; input to a specific timing specific period setting circuit, input the output of the specific timing specific period setting circuit to the steady pulse output setting circuit, the specific time pulse output setting circuit, and the changeover switch circuit; The output of the steady state pulse output setting circuit and the specific time pulse output setting circuit are input, the output of the changeover switch circuit is used as a setting command signal for setting the magnitude of the laser output, and the output of the detection circuit is used as the setting command signal for setting the magnitude of the laser output. A CO_2 gas laser control device characterized in that a setting command signal when outputting a laser pulse is changed only for a specific period at a specific timing. (2) The pulse peak value of the steady-state pulse frequency and the specific-time pulse frequency setting circuit, the changeover switch circuit for switching between the steady-state pulse frequency and the specific-time pulse frequency, and the former steady-state pulse output setting circuit; a pulse output setting circuit comprising a pulse width setting circuit; a waveform conversion circuit for setting a pulse peak value of the specific time pulse output setting circuit, and a pulse width and a rising slope and a falling slope of the pulse output; a pulse waveform conversion circuit including a changeover switch for switching between the output of the waveform conversion circuit and the output of the pulse output setting circuit; the detection circuit and the specific timing specific period setting circuit; is input to the specific timing specific period setting circuit, the output of the specific timing specific period setting circuit is input to the pulse output setting circuit and the pulse waveform conversion circuit, and the output of the pulse output setting circuit is input to the pulse waveform conversion circuit. , the output of the pulse waveform conversion circuit is used as a setting command signal for setting the magnitude of the laser output, and the output of the detection circuit is used to change the setting command signal at the time of laser pulse output only at a specific timing and for a specific period. A CO_2 gas laser control device characterized by: (3) The steady-state pulse output setting circuit, the pulse waveform conversion circuit, and the detection circuit are provided, and the output of the detection circuit is input to the steady-state pulse output setting circuit and the pulse waveform conversion circuit, and the pulse The output of the steady state pulse output setting circuit is input to the waveform conversion circuit, the output of the pulse waveform conversion circuit is used as a setting command signal for setting the magnitude of the laser output, and the output of the detection circuit is used to set the laser pulse output. A CO characterized by changing the command signal.
_2 Gas laser control device. (4) The output of the detection circuit is input to a delay circuit, and the output of the delay circuit is input to the specific timing specific period setting circuit, the steady pulse output setting circuit, and the pulse waveform conversion circuit. Claims 1 to 3
CO_2 gas laser control device according to any one of the above. (5) In the pulse output waveform of the steady state pulse output setting circuit, a second pulse peak value higher than the steady pulse peak value or lower than the steady pulse peak value is set to the second pulse peak value after a first time limit from the rise of the pulse output. 5. The CO_2 gas laser control device according to claim 1, wherein the CO_2 gas laser control device uses a steady state pulse output that is provided for only a second time period and returns to the original steady pulse peak value after the second time period. (6) The specific timing and specific period of the specific timing specific period setting circuit, the second pulse peak value, the first time period, the second time period, and the specific time pulse output setting circuit of the steady state pulse output setting circuit. pulse peak value, pulse width, pulse frequency, pulse rising slope,
The pulse frequency of the falling slope and pulse output setting circuit, the pulse peak value, pulse width, pulse rising slope, falling slope of the pulse waveform conversion circuit, and the delay time of the delay circuit are determined by the laser output, laser processing speed, or discharge. Tube discharge voltage, discharge current, injected power, or laser gas flow rate or laser gas pressure, or laser assist gas flow rate or laser assist gas pressure, or table vibration of processing equipment, or reflected light from the front or back surface of the workpiece, or 6. The CO_2 gas laser control device according to claim 1, wherein the CO_2 gas laser control device is a function of scattered light, temperature of the front or back surface of the workpiece, or a laser beam mode waveform. (7) A signal voltage proportional to the magnitude of the laser output is input to the detection circuit, a comparator is provided to which the signal voltage and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. Alternatively, a signal voltage proportional to the magnitude of the laser output is input to a differentiating circuit, a comparator is provided to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. The CO_2 gas laser control device according to any one of claims 1 to 6. (8) A signal voltage proportional to the magnitude of the laser processing speed is input to the detection circuit, a comparator is provided to which the signal voltage and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. Alternatively, a signal voltage proportional to the magnitude of the laser processing speed is input to a differentiating circuit, a comparator is provided to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. The CO_2 gas laser control device according to any one of claims 1 to 6, characterized in that: (9) A signal voltage proportional to the discharge voltage generated in the discharge tube, the discharge current flowing in the discharge tube, or the magnitude of the power injected into the discharge tube is input to the detection circuit, and the signal voltage and the set reference voltage are A comparator is provided, and the output of the comparator is used as the output of the detection circuit, or the output of the comparator is proportional to the discharge voltage generated in the discharge tube, the discharge current flowing in the discharge tube, or the magnitude of the power injected into the discharge tube. Claims 1 to 6 characterized in that a signal voltage is input to a differentiating circuit, a comparator is provided to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. CO_2 gas laser control device according to any one of the above. (10) A signal voltage proportional to the gas flow rate or gas pressure of the laser gas flowing in the discharge tube is input to the detection circuit, and a comparator is provided to which the signal voltage and a set reference voltage are input, and the comparator The output of the detection circuit is set as the output of the detection circuit, or a signal voltage proportional to the gas flow rate or gas pressure of the laser gas flowing in the discharge tube is input to the differentiator circuit.
CO_2 according to any one of claims 1 to 6, further comprising a comparator to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit.
Gas laser control device. (11) A signal voltage proportional to the magnitude of the laser assist gas flow rate or gas pressure in the laser processing nozzle section is input to the detection circuit, and a comparator is provided to which the signal voltage and a set reference voltage are input, and the comparison is performed. The output of the detector is used as the output of the detection circuit, or a signal voltage proportional to the laser assist gas flow rate or gas pressure in the laser processing nozzle is input to the differentiating circuit, and the output of the differentiating circuit and the set reference voltage are 7. The CO_2 gas laser control device according to claim 1, further comprising a comparator for input, and the output of the comparator is used as the output of the detection circuit. (12) A signal voltage proportional to the magnitude of table vibration of the laser processing device is input to the detection circuit, a comparator is provided to which the signal voltage and a set reference voltage are input, and the output of the comparator is detected by the detection circuit. A signal voltage proportional to the magnitude of the table vibration of the laser processing device is input to the differentiating circuit, and a comparator is provided to which the output of the differentiating circuit and the set reference voltage are input. 7. The CO_2 gas laser control device according to claim 1, wherein the output is an output of a detection circuit. (13) A comparator that inputs a signal voltage proportional to the magnitude of laser reflected light or laser scattered light from the front surface of the workpiece or the back surface that has passed through the detection circuit, and inputs the signal voltage and a set reference voltage. The output of the comparator is set as the output of the detection circuit, or a signal voltage proportional to the magnitude of the laser reflected light or the laser scattered light on the surface of the workpiece or the back surface through which it has passed is input to the differentiating circuit. Claim 1 characterized in that a comparator is provided to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit.
7. The CO_2 gas laser control device according to any one of 6 to 6. (14) A signal voltage proportional to the surface temperature of the workpiece on the front side of the workpiece or the back side through which it has passed is input to the detection circuit, and a comparator to which the signal voltage and a set reference voltage are inputted. The output of the comparator is set as the output of the detection circuit, or the signal voltage proportional to the surface temperature of the workpiece on the front side of the workpiece or the back side of the workpiece passed through is input to a differentiator circuit, and the output of the comparator is set as the output of the detection circuit. 7. The CO_2 gas laser control device according to claim 1, further comprising a comparator to which the output of the circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit. (15) A signal voltage proportional to the degree of relative deviation from the normal reference mode waveform of the laser beam is input to the detection circuit, and a comparator is provided to which the signal voltage and a set reference voltage are input, and the comparison is performed. The output of the detector is used as the output of the detection circuit, or a signal voltage proportional to the degree of relative deviation from the normal reference mode waveform of the laser beam is input to the differentiator circuit.
CO_2 according to any one of claims 1 to 6, further comprising a comparator to which the output of the differentiating circuit and a set reference voltage are input, and the output of the comparator is used as the output of the detection circuit.
Gas laser control device. (16) The CO_2 gas laser control device according to any one of claims 1 to 6, wherein the detection circuit is a cutting process start command signal circuit or a cutting process end command signal circuit for laser cutting.