JPH08236846A - Laser oscillator - Google Patents

Abstract

PURPOSE: To provide a laser oscillator having excellent response and stable output. CONSTITUTION: An oscillator control part 5 receives a laser output command signal 23 from an NC equipment 3, converts the signal 23 to a direct voltage waveform command signal 25, and transfers it to a power supply part through an adder 7. The power supply part receives the voltage waveform command signal 25, supplies discharge power, and generates a laser light LB from an oscillation head 15. A laser light output detector 21 detects the laser light LB, and transfers a light output detection signal 27 to a comparator 19. A simulator 17 estimates response characteristics form the power supply part to the laser light output detector 21, simulates the voltage waveform command signal 25, and transfers it to the comparator 19. It obtains the deviation of the light output detection signal 27 from the signal from the simulator 17, and transfers the deviation to the adder 7. The adder 7 sets the deviation from the comparator 19 as a negative signal, adds it to the voltage waveform command signal 25, and corrects it, which is transferred to the power supply part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillator,
More specifically, the present invention relates to a laser oscillator having good response and stable output.

[0002]

2. Description of the Related Art Conventionally, an oscillator 101 of a laser beam machine
For example, the one disclosed in JP-A-4-35078 is known. That is, as shown in FIG. 5, the first signal processing unit 105 converts commands such as the frequency, duty, and amplitude issued from the NC device 103 into the optical waveform command signal 107, and the second signal processing unit 109. Communicate to.

The second signal processing unit 109 converts the optical waveform command signal 107 into a voltage waveform command signal 111, and the power supply unit 1
Sent to 13. The power supply unit 113 includes a DCPU 115 and an RFPU 117. The DCPU 115 obtains a DC variable voltage from a commercial power source and performs pulse modulation and the like. Further, the RFPU 117 converts DC voltage into RF (high frequency alternating current) and high voltage (about 5000 V),
A laser beam LB is emitted from the oscillation head 119.

The laser beam LB emitted from the oscillation head 119 is detected by the optical sensor 121 and the optical output detection signal 12
3 is sent to the comparator 125. On the other hand, the optical waveform command signal 107 from the first signal processing unit 105 is the CR filter 1
A laser output command signal matched with the response characteristic of the optical sensor 121 is sent to the comparator 125 by 27. The comparator 125 receives the optical output detection signal 123, which is a feedback signal input from the optical sensor 121, and the CR filter 1
The deviation from the laser output command signal from 27 is calculated and added to the optical waveform command signal 107 from the first signal processing unit 105 to correct it.

Therefore, the second signal processing unit 109 converts the corrected optical waveform command signal 107 into the voltage waveform command signal 111 and emits the laser beam LB as described above.

[0006]

However, in such a conventional technique, the optical waveform command signal 107 is set to C
The optical output detection signal 12 is passed through the R filter 127.
3 is predicted. This can be easily considered, but there is a problem that the prediction is not always correct due to non-linear elements such as base discharge.

Further, the oscillation head 119 emits the laser beam LB in response to the voltage waveform command signal 111 issued by the second signal processing unit 109, and the optical sensor 121 detects the laser beam LB and sends the optical output detection signal 123 to the comparator 125. Further, since the second signal processing unit 109 is in the closed loop of sending this to the second signal processing unit 109, there is a problem that the response is delayed and it is not practical, and the optical output becomes unstable.

That is, referring to FIG. 6, in response to the optical waveform command signal 107 (see (A) in FIG. 6), the optical sensor 1
There is a problem that the response of the optical output detection signal 123 (see (B) in FIG. 6) detected by 21 requires a time several times the time constant of the optical sensor 121 (τ1 in FIG. 6B).

Further, there is a problem in that it is necessary to generate the optical waveform command signal once, and a wasteful time is required for processing.

An object of the present invention was made in view of the above-mentioned conventional techniques, and it is an object of the present invention to provide a laser oscillator having good response and stable output.

[0011]

In order to achieve the above object, a laser oscillator of the present invention according to claim 1 includes an oscillator control unit for receiving a laser output command signal from an NC device and converting it into a voltage waveform command signal. , A power supply unit that receives a voltage waveform command signal from the oscillator control unit and supplies discharge power, and an oscillation head that emits laser light by the power from the power supply unit, and detects the laser light from the oscillation head From a laser light output detector, a simulator that receives the voltage waveform command signal and predicts response characteristics from the power supply unit to the laser output detector, and a light output detection signal from the laser light output detector and the simulator And a adder for negatively feeding back the deviation from the comparator to the voltage waveform command signal. It is.

[0012]

In the laser oscillator according to the first aspect of the invention, the laser output command signal from the NC device is received, the oscillator control unit converts the signal into a voltage waveform command signal, and the signal is transmitted to the power supply unit through the adder. The power supply unit receives the voltage waveform command signal from the oscillator control unit, supplies discharge power, and emits laser light from the oscillation head. The laser output detector detects the emitted laser light and transmits the optical output detection signal to the comparator. On the other hand, the simulator receives the voltage waveform command signal, predicts the response characteristic from the power supply unit to the laser output detector, and transmits it to the comparator. The comparator takes the deviation between the optical output detection signal from the laser output detector and the signal from the simulator, and transfers it to the adder. The adder corrects this by adding the deviation from the comparator as a negative signal to the voltage waveform command signal from the oscillator control unit, and transmits it to the power supply unit.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the laser oscillator of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of the laser oscillator 1. That is, the NC device 3 includes the oscillator controller 5
Is connected to the oscillator control section 5, and the oscillator control section 5 is provided with a first signal processing section 5A and a second signal processing section 5B, and the oscillator control section 5 is connected to the DCPU of the power supply section 9 via the adder 7.
11, an oscillation head 15 (for example, a triaxial orthogonal carbon dioxide laser oscillator) is connected via the RFPU 13. A simulator 17 is connected to the oscillator controller 5, and further connected to the adder 7 via a comparator 19. On the other hand, an optical sensor 21 as a laser light output detector for detecting the laser light LB emitted from the oscillation head 15 is provided, and this optical sensor 21 is connected to the comparator 19.

Therefore, the laser output command signal 23 such as frequency, duty, amplitude, etc. is sent from the NC device 3 to the oscillator controller 5.
The first signal processing unit 5 of the oscillator control unit 5
At A, the laser output command signal 23 is converted into an optical waveform command signal and transmitted to the second signal processing section 5B. The second signal processing unit 5B converts the optical waveform command signal into the voltage waveform command signal 25. The voltage waveform command signal 25 is transmitted to the DCPU 11 of the power supply unit 9 via the adder 7.

The DCPU 11 obtains a DC variable voltage from a commercial power source and performs pulse modulation and the like, and further, the RFPU 13 converts the DC voltage into RF (high frequency alternating current) and high voltage, and the oscillation head 15 emits a laser beam LB. The optical sensor 21 detects this laser beam LB and sends an optical output detection signal 27 to the comparator 19.

On the other hand, the voltage waveform command signal 25 from the oscillator controller 5 is also sent to the simulator 17 and further to the comparator 19 to detect the optical output signal 27 from the optical sensor 21.
And the deviation is sent to the adder 7 and added as a negative signal to the voltage waveform command signal 25 to correct it.

The simulator 17 is the above-mentioned DCPU1.
1, the operation of the oscillation head 15 from the RFPU 13 and the operation of the optical sensor 21 for detecting the laser beam LB are simulated.

That is, referring to FIGS. 2 and 3 together, the simulator 17 starts the discharge start V0 and the oscillation start V1.
Up to the nonlinearity and the optical output detection signal 2 of the optical sensor 21
The delay τ of 7 is simulated, and even within the transient time of the output of the optical sensor 21, the optical output detection signal 27 from the optical sensor 21 and the command value from the simulator 17 are compared to obtain a deviation, and this deviation is used as a correction value. It is transmitted to the adder 7.

According to such a laser oscillator, the simulator 17 simulates the non-linearity until the start of discharge or the start of oscillation and the delay of the optical output detection signal 27 of the optical sensor 21, so that the transient time of the output of the optical sensor 21 is increased. In the inside, the optical output detection signal 27 from the optical sensor 21 is compared with the command value from the simulator 17, and the voltage waveform command signal 2
Since 5 is corrected, optimum correction is always added, and control with good responsiveness is performed.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. For example, the signal processing can be performed digitally or software. In this case, the processing speed is slightly reduced, but there is an advantage that the tuning can be automated.

Further, the voltage waveform command signal 25 shown in FIG.
May be a waveform of current or power corresponding to discharge power.

[0023]

In the laser oscillator according to the first aspect of the present invention, the laser controller receives the laser output command signal from the NC device and directly converts it into the voltage waveform command signal. Processing time can be shortened because it is not necessary to perform conversion. The voltage waveform command signal from the oscillator control unit is transmitted to the power supply unit via the adder, and the power supply unit receives the voltage waveform command signal and supplies the discharge power to emit laser light from the oscillation head. The laser output detector detects the emitted laser light and transmits the optical output detection signal to the comparator. On the other hand, the simulator predicts the response characteristic from the power supply unit to the laser output detector, simulates the voltage waveform command signal so as to have the same characteristic, and transmits it to the comparator, and the comparator detects the laser output. The difference between the optical output detection signal from the detector and the signal from the simulator is transmitted to the adder, and the adder adds the deviation from the comparator as a negative signal to the voltage waveform command signal from the oscillator controller. By doing so, this is corrected and transmitted to the power supply unit. Thereby, even if the response characteristic from the power supply unit to the laser output detector is non-linear or there is a delay, optimum correction is always added. Further, since the conventional second signal processing unit does not exist in the closed loop formed by the adder, the power supply unit, the oscillation head, the laser output detector, and the comparator, stable response and stable control are possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a laser oscillator according to the present invention.

FIG. 2 is a graph showing the relationship between DCPU output voltage and laser output.

FIG. 3 is a graph showing an output of an optical sensor that receives laser light.

FIG. 4 is a graph showing the output command signal and the output of the optical sensor in the laser oscillator according to the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional laser oscillator.

FIG. 6 is a graph showing a conventional output command signal and the output of the optical sensor.

[Explanation of symbols]

 1 Laser Oscillator 3 NC Device 5 Oscillator Control Section 7 Adder 9 Power Supply Section 15 Oscillating Head 17 Simulator 19 Comparator 21 Optical Sensor (Laser Light Output Detector) 23 Laser Output Command Signal 25 Voltage Waveform Command Signal 27 Optical Output Detection Signal LB Laser light

Claims (1)

[Claims] 1. An oscillator control unit that receives a laser output command signal from an NC device and converts it into a voltage waveform command signal; a power supply unit that receives the voltage waveform command signal from this oscillator control unit and supplies discharge power. A laser light output detector that has an oscillation head that emits laser light by power from this power supply unit, detects the laser light from this oscillation head, and detects the laser output from the power supply unit by receiving the voltage waveform command signal. A simulator for predicting response characteristics up to the detector, a comparator for taking a deviation between the optical output detection signal from the laser light output detector and the signal from the simulator, and the deviation from the comparator to the voltage waveform command signal A laser oscillator comprising: an adder for negatively feeding back to the.