JP2684107B2 - Numerical controller for laser beam machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a numerical control device for a laser processing machine.

2. Description of the Related Art FIG. 4 shows an example of a laser processing machine using a conventional general-purpose numerical control device (hereinafter abbreviated as general-purpose NC device).
In FIG. 4, 1 is an NC control unit, 2 is an NC sentence analysis unit, 3 is a sequence control unit, 4 is a servo motor, 5 is a machining table, 6 is a laser output control unit, 7 is a laser oscillator, and 8 is user machining. It is a program.

NC composed of NC sentence analysis unit 2 and sequence control unit 3
The control unit 1 drives the servo motor 4 and moves the machining table 5 according to the input user machining program 8. At the same time, a command is given to the laser output control unit 6 to control the output of the laser light and the flow rate of the auxiliary gas.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in such a conventional general-purpose NC device, when the cylinder of the auxiliary gas is emptied during processing or the gap control of the laser light delivery nozzle and the workpiece becomes an alarm, Since it became impossible to continue the processing, it was necessary to stop the table movement and laser output to stop the alarm.

However, when these obstacles are recovered and machining is restarted, the table movement can be continued because the machining program is still in progress, but the laser output control is performed before the moving machining part of the normal program with the output condition setting. Therefore, there is a problem that the laser beam cannot be sent out during the movement, and the processing must be performed by returning to the beginning of the program.

Further, in a laser processing machine, sheet metal processing is generally used, and many large-scale processing such as 4 × 8 is used, and a large-capacity processing program is used.
As a result, an alarm such as a gas shortage that occurs on a daily basis often causes a stop during the program, and the program start and laser output are set each time.
It was necessary to find the NC program statement and restart machining, which hindered the smooth continuation of laser machining.
Further, for this reason, laser processing cannot be automatically restarted.

The present invention solves such a conventional problem, and holds the NC laser output control condition and feed rate during machining as a process record, and when an alarm is stopped in the middle of the program, the process record It is an object of the present invention to provide a numerical control device for a laser processing machine capable of automatically restarting processing from a stop position according to the above.

Means for Solving the Problems The present invention, in order to achieve the above object, according to a user machining program, an NC statement analysis unit that drives a servomotor and commands a sequence control unit, and an NC statement analysis unit and a sequence control unit. Process log storage section that stores the laser processing conditions that determine the behavior of the part and the stop position of the laser processing, and the restart procedure of the laser processing based on the laser processing conditions held in this process log storage section at the time of restart. And a restart sequence creation unit that controls creation.

Action The present invention has the above-described configuration, in which the laser control conditions and the feed rate during the laser processing process are sequentially stored in the laser control storage unit as a process log, and after removing an obstacle at the time of alarm stop, the storage conditions are based on these storage conditions. By restarting the laser oscillator from the stop position, machining can be restarted from the stop position, so even if an alarm is stopped during machining of a long product, machining can be restarted smoothly without wasting time and materials. it can.

Embodiment FIG. 1 shows the configuration of a numerical controller for a laser processing machine according to an embodiment of the present invention. In FIG. 1, 11 is
NC control unit, 12 is an NC sentence analysis unit, 13 is a sequence control unit, 14
Is a process log storage unit, 15 is a restart sequence creation unit, 16 is a servo motor, 17 is a machining table, 18 is a laser output control unit, 19 is a laser oscillator, and 20 is a user machining program.

Next, the operation of this embodiment will be described. The user machining program 20 is analyzed by the NC statement analysis unit 12 in the NC control unit 11, the servo motor 16 is driven, and the sequence control unit
Driving the laser output control unit 18 by means of 13 is the same as in the prior art, but in the present embodiment, the process log storage unit 14 provided in the NC control unit 11 has, for example, piercing as shown in FIG. The contents of the laser processing condition table 23 including the condition 21 and the cutting condition 22 and the machine position are stored.

Generally, output control of a laser processing machine is performed by laser output value P, laser pulse output frequency Q, laser pulse duty ratio R
And the table feed speed F. Therefore, as a preparation function of the laser NC, the NC statement analysis unit is configured so that the following conditions can be specified in the machining program.

G82 P_Q_R_F_; P: Laser output value (W) Q: Laser pulse output frequency (Hz) R: Laser pulse duty ratio (%) F: Table feed speed (mm / min) Also, the preparatory function specified in the machining program. On the other hand, power override and feed rate override are applied from the NC operation unit so that proper machining conditions can be selected.

When alarms such as auxiliary gas empty are generated, the NC controller 11 is instructed to restart after canceling the troubles. In response to the restart command, the restart sequence creation unit 15 retrieves the contents of the process log storage unit 14 and operates the automatic sequence for restarting laser processing, and restarts processing from the machine position also stored in the process log storage unit 14. .

FIG. 3 shows an example of an automatic sequence for restarting laser processing in the restart sequence creating unit 15. The restart sequence creation unit 15 first takes out the piercing condition 21 from the process log storage unit 14, gives it to the laser output control unit 18 as a preparation command, then selects the type of auxiliary gas, and uses the stored gas pressure. Release auxiliary gas. Further, the scanning for keeping the gap with the work piece constant is started, and the laser output controller 18 is instructed to start the oscillation. Next, the shutter is opened to irradiate the laser beam, and waits for a certain period of time to complete the piercing. This is because the case where the table stop was delayed after the laser oscillation was stopped when the alarm was stopped was considered.

Next, the cutting condition 22 described in the process log storage unit 14 is taken out and the laser output control unit 18 is instructed. Similarly, the auxiliary gas discharge switching is performed with the stored gas type and gas pressure, and a series of machining restart sequence is completed, and the machining from the similarly stored machine position is continued.

EFFECTS OF THE INVENTION As is clear from the above embodiments, according to the numerical control device for a laser processing machine of the present invention, a process log storage unit that stores the processing condition and the processing position when the alarm is stopped, and the process log storage unit. With a restart sequence creation unit that creates a restart procedure for laser processing based on the processing conditions stored in, the laser processing can be restarted smoothly from the alarm stop position without requiring any special operation. Even if an alarm is stopped during processing, processing can be continued without wasting time and materials, and its industrial utility value is great.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a numerical control device for a laser processing machine according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing an example of a laser processing condition table in the device,
FIG. 3 is an explanatory diagram showing an example of a restart sequence in the apparatus, and FIG. 4 is a block diagram showing an example of the configuration of a conventional numerical control device for a laser processing machine. 11 …… NC control unit, 12 …… NC sentence analysis unit, 13 …… Sequence control unit, 14 …… Servo motor, 15 …… Machining table, 16
...... Laser output control unit, 17 ・ ・ ・ Laser oscillator, 18 ・ ・ ・ User machining program, 19 ・ ・ ・ Process log storage unit, 20 ・ ・ ・ Restart sequence creation unit, 21 ・ ・ ・ Piercing conditions, 22 ・ ・ ・
… Cutting conditions, 23… Laser processing condition table.

Claims (1)

(57) [Claims] 1. An NC statement analysis section that drives a servomotor and commands a sequence control section according to a user processing program, a laser processing condition that determines the behavior of the NC statement analysis section and the sequence control section, and a stop of laser processing. A process log storage unit that stores the position, and a restart sequence creation unit that creates and controls a restart procedure of laser processing based on the laser processing conditions held in the process log storage unit at the time of restart,
A numerical control device for a laser processing machine, characterized in that after the alarm is stopped, the laser processing is automatically continued from the stop position in accordance with the laser processing restart procedure created by the restart sequence creation unit.