JPH05138374A - Controller for output of laser beam machine - Google Patents

Abstract

PURPOSE:To enable a working with the optimum laser intensity by calculating a laser intensity data uniformizing the irradiating energy density of laser beam for the work and sending the data to an output adjusting part of a laser oscillator. CONSTITUTION:The operation of a machine main body 1 is commanded and controlled by a numerical controller 2. The work is irradiated with laser beam by the laser oscillator and the intensity of the laser beam is adjusted at an output adjusting part according to the intensity data of the laser beam. Actual speed data showing the actual speed of a machine main body 1 is input by a sequencer 3 from an numerical controller 2, laser strength data always to uniformize the irradiating energy density per unit time of laser beam to the work is calculated based on this actual speed, laser intensity data is sent to an output adjusting part of the laser oscillator 4. In this way, the laser output can automatically be controlled according to the moving speed of the laser beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output control device for a laser processing machine, which automatically controls laser output according to the speed at which a laser beam moves along a processing line.

[0002]

2. Description of the Related Art In an NC laser beam machine, a machine body is equipped with a laser oscillator, and the operation of the machine body is controlled by an NC device. That is, the operation of the machine body is controlled by the NC device so that the laser beam output from the laser oscillator is irradiated along the processing line. In such laser processing, it is necessary to control the laser intensity to a value suitable for the feeding speed of the laser beam along the work processing line. Conventionally, the laser intensity has been manually set by an operator or set by NC program data.

[0003]

As described above, in laser processing, it is necessary to control the laser intensity so that it is most suitable for the feeding speed of the laser beam to the work. Conventionally, in the NC laser processing machine, the laser intensity is manually set in advance or set as intensity data in the NC program. However, in actual NC processing, when the speed changes as shown in FIG. 8 or when the corner portion is accelerated or decelerated as shown in FIG. 9, the laser intensity is not optimal in that section, and the processing state becomes uneven. It was the cause.

That is, at the speed change shown in FIG. 8, if the feed speed command is changed from speed 1 to speed 2 by the NC tape, the laser intensity also changes stepwise by the NC tape command. On the other hand, the actual feed rate (ACTUA
Since L) gradually changes from speed 1 to speed 2, it is ideal that the laser intensity also gradually changes in accordance with this, but the laser intensity changes stepwise. For this reason, the laser irradiation amount becomes excessive in the section in which the actual feed speed is accelerated from speed 1 to speed 2. For the same reason, when decelerating from speed 2 to speed 1, the laser irradiation amount becomes insufficient.

9 (a) and 9 (b) show a state in which the corners α to β (FIG. 9 (a)) are moved by linear interpolation (FIG. 9 (b)).
Is shown. NC at corners α to β
Since the actual feed rate is reduced by the automatic acceleration / deceleration function of the device, it is ideal if the laser intensity is also reduced accordingly, but in reality, the laser intensity command is constant and the laser intensity is also constant. Therefore, excessive laser irradiation occurs at the corners α to β.

After all, in the prior art, as shown in FIGS. 8 and 9, the laser intensity cannot be changed in accordance with the actual feed rate, so that the laser beam is excessively or insufficiently irradiated to the workpiece. Occur. Therefore, the NC laser processing machine has been impractical in the field where uniform heating per unit time is required, such as scribing a coating film coated on a metal plate.

[0007]

As shown in FIG. 1, the present invention comprises a machine body 1, an NC device 2, a sequencer 3 and a laser oscillator 4, and the connection between the NC device 2 and the sequencer 3 and the sequencer 3 and the laser. The connection with the oscillator 4 is of a system that allows data transmission in real time (analog signal or parallel digital signal). The laser oscillator 4 is also capable of adjusting the output in real time according to the input laser intensity data.
The sequencer 3 has a built-in program to control this system. It has a function to input the actual speed of the machine body 1 from the NC device 2 in real time, convert it to the optimum laser intensity data and immediately send it to the laser oscillator 4. Attached.

[0008]

The operation of the present invention will be described based on the flowchart of the sequencer program shown in FIG. The sequencer 3 first inputs the actual speed of the machine body 1 from the NC device 2 in step 1, and converts the actual speed into the optimum laser intensity in step 2. The conversion formula used here is laser, work,
The energy density per unit time of the laser with respect to the work is determined so as to be always constant, taking into consideration the characteristics of the machine and the like. In step 3, the laser intensity data is sent to the laser oscillator 4 and the intensity of the output laser is controlled. By repeatedly executing the above processing in a time shorter than the time required for the acceleration / deceleration of the machine body 1, it becomes possible to control the optimum laser intensity corresponding to the actual speed of the machine body 1.

[0009]

EXAMPLE FIG. 3 shows the appearance of a laser scribing machine as an example. In this machine, a coating material applied on the surface of an aluminum workpiece 12 is scribed by a laser beam with a 5-axis head 11. The laser oscillator 15 and the laser power supply unit 14 are the long gantry 1
It is mounted on the slide part of No. 6. A sequencer for controlling the laser intensity is built in the NC device 13,
MI function (Basic Machine Interface)
ace: It is possible to input the actual speed of the NC machine by the internal information [position, speed] of the NC device and the function of the sequencer that reads out at high speed. The NC device 13 and the laser power supply unit 14 are connected by a two-core cable,
The laser intensity command is transmitted by an analog signal of 0 to 10V.

FIG. 4 shows a block diagram of the laser intensity automatic control. The NC device 13 includes an NC controller 13a and a sequencer 1
3b, and the machine body 17 is driven by each axis servo unit 18 and each axis servo motor 19. The movement of the machine body 17 is input as an actual speed to the sequencer 13b via the NC control unit 13a. Sequencer 13b
Calculates the optimum laser intensity from this data and outputs it as a command voltage signal to the NC control unit 13a, which then outputs it to the laser power supply unit 14, and the CO ₂ laser oscillator 15 is finally controlled.

FIG. 5 shows a flow chart for calculating the command voltage signal value. In step 11, the actual NC speed is the NC control unit 13a.
Input to the sequencer 13b, and then step 12
At that time, the laser emission is judged to be ON / OFF, and if it is OFF, the following processing is ignored. In step 13, the conversion from the actual speed data to the strength command data is performed by multiplying by 0.8191 as shown in the following expression (1).

[0012]

## EQU1 ## Strength command voltage signal value = Fa × 8191/10000 (1) where Fa: actual speed input from NC control unit

By analog-outputting the calculation result in step 14, an analog voltage of 0 to 10 [V] is sent to the laser power supply unit 14 as a laser intensity command.

Thus, the intensity command voltage signal value is 0 to 819.
1, the NC controller 13a outputs 0 to 10 [V], while the laser output outputs 0 to 100 [W] in a linear change. The actual speed at 100 [W] is 10,000 [mm / min].

Here, as shown in FIG. 4, the laser intensity command is sent from the sequencer 13b to the laser power supply unit 14 via the NC control unit 13a as the spindle command voltage because the NC control unit 13a originally has the spindle control. This is because the analog voltage output function for is used.

In the flow chart shown in FIG. 5,
The time (scan time) required to execute a series of processes is 8 [msec], and the acceleration / deceleration time constant of the present laser scribing machine is 0.5 [sec]. Therefore, the maximum speed is reached from the stopped state. Between 0.5 / 0.00
The laser intensity can be adjusted 8 = 62.5 times.

Since the laser output is controlled according to the movement of the machine body 17 as described above, the irradiation energy density of the laser beam per unit time to the work can be always made uniform and optimum laser irradiation can be performed. For example, in FIG.
As shown in, when the feed speed command changes from speed 1 to speed 2 and the actual feed speed gradually increases,
The laser intensity also follows and gradually increases. See also FIG.
As shown in, when the actual feed speed once decreases and then returns to the original speed at the corner portion, the laser intensity also follows the laser intensity and then decreases and then returns to the original intensity.

[0018]

According to the present invention, even if the feed rate of the laser beam is changed by laser processing of a workpiece having a two-dimensional or three-dimensional complicated processing line, all lines including the straight line portion and the curved line portion are processed. Now, it is possible to process with the optimum laser intensity.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a block diagram showing the basic operation of the present invention.

FIG. 3 is a perspective view showing a laser scribing machine that is an embodiment of the present invention.

FIG. 4 is a block diagram showing a control system of the embodiment.

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is a characteristic diagram showing a control state of the embodiment when the speed changes.

FIG. 7 is a characteristic diagram showing a control state of the embodiment in the corner portion.

FIG. 8 is a characteristic diagram showing a control state of the related art when the speed changes.

FIG. 9 is a characteristic diagram showing a control state of the related art when the speed changes.

[Explanation of symbols]

 1 Machine Main Body 2 NC Device 3 Sequencer 4 Laser Oscillator 11 5 Axis Head 12 Work 13 NC Device 13a NC Controller 13b Sequencer 14 Laser Power Supply Unit 15 Laser Oscillator 16 Long Gantry 17 Machine Main Body 18 Various Servo Units 19 Various Servo Motors

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hiroo Nabeta, 10 Oemachi, Minato-ku, Nagoya, Aichi Prefecture, Nagoya, Japan Aerospace Systems Works, Mitsubishi Heavy Industries, Ltd. (72) Toshiro Ota Oe-machi, Minato-ku, Aichi Prefecture No. 10 Mitsubishi Heavy Industries, Ltd., Nagoya Aerospace Systems Works (72) Inventor Toshihide Naka, No. 10, Oemachi, Minato-ku, Nagoya, Aichi Prefecture Mitsubishi Heavy Industries, Ltd., Nagoya Aerospace Systems Works

Claims (1)

[Claims] 1. A machine body, an NC device for command-controlling the operation of the machine body, irradiating a laser beam toward a work provided in the machine body, and a laser beam according to input laser intensity data. And a laser oscillator having an output adjusting unit for adjusting the intensity of the laser beam, and the actual speed data indicating the actual speed of the machine body are input from the NC device. Based on the actual speed data, the laser beam is irradiated to the workpiece per unit time. An output control device for a laser processing machine, comprising: a sequencer that calculates laser intensity data that makes the energy density always uniform and sends the laser intensity data to an output adjustment unit of the laser oscillator.