JPH05220591A - Electric shutter method for laser beam machine - Google Patents

Abstract

PURPOSE:To provide an electric shutter method in which a laser output is zero at the time of interrupting the machining and a prescribed laser output is quickly generated at the time of restarting the machining, in a laser beam machine. CONSTITUTION:In the laser beam machine, when the machining is interrupted, the electric discharge of the laser beam is switched from the discharge at the time of machining to the pulse discharge whose time width is 50mus or less, the electric discharge is continued, and simultaneously the laser output Pl is made zero; when the machining is restarted, the pulse discharge is switched to the electric discharge at the time of machining, and a required laser output Pl is quickly generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric shirt method for a laser beam machine.

[0002]

2. Description of the Related Art In a laser processing machine, an electric shirt is usually used to prevent damage caused on the surface of a workpiece by laser light when waiting for processing or moving the workpiece. The laser light is not emitted from. The electric shirt lowers the discharge current to the "threshold" at which the laser output becomes zero when the above-mentioned processing is interrupted,
When the processing is restarted, the discharge current is rapidly increased to generate a predetermined laser output.

Since the carbon dioxide laser processing machine has a large output and efficiency, it is often used for various laser processing. However, since the gain is high, the "threshold" of the discharge current is low and the laser output is zero. Reducing the discharge current makes it difficult to maintain the discharge. Further, if the discharge current is increased from such a state at the time of resuming processing, arc discharge is likely to occur and the laser output becomes unstable. Therefore, in a carbon dioxide laser processing machine, a discharge current slightly higher than the "threshold value" is supplied by a simmer power supply provided for maintaining discharge, and the slight laser light generated by the simmer discharge causes mechanical shirting. Was absorbed by.

[0004]

As described above, in the carbon dioxide gas laser processing machine, the slight laser light generated by the simmer discharge is absorbed by the mechanical shirt, but the drilling is continuously performed. In some cases, it takes a considerable amount of time to operate the mechanical shirt, and there is a problem that the entire processing time becomes long. As one of the countermeasures, increasing the transmittance of the mirror on the output side of the oscillator may be considered, but doing so causes a problem that the output of the laser is totally lowered and the efficiency is lowered. It didn't work.

When a laser is generated in a carbon dioxide laser processing machine by electric discharge, there is a delay of about 50 μs from the electric discharge to the generation of laser light.
Therefore, conversely, even if a pulse having a time width of 50 μs or less is repeatedly supplied between the electrodes, laser light is not generated. The present invention was devised with this point in mind, and by means such as that described below, the laser output can be reliably reduced to zero even without using a mechanical shutter when waiting for processing or when moving a workpiece. In addition, an object of the present invention is to provide an electric shirt method capable of promptly generating a required laser output when resuming processing.

[0006]

In order to achieve the above-mentioned object, an electric shirt method for a laser beam machine according to the present invention comprises:
In the laser processing machine, when the processing is interrupted, the electric discharge of the laser oscillator is switched from the electric discharge during the processing to the pulse electric discharge with a time width of 50 μs or less, the electric discharge is continued and the laser output is made zero, and the pulse electric discharge during the processing is restarted. The discharge is switched to generate the required laser output promptly.

[0007]

With this configuration, when the laser discharge is switched from the machining discharge to the pulse discharge having a time width of 50 μs or less when the machining is interrupted, the laser output immediately becomes zero, which damages the workpiece or the like. Don't worry. Further, since the electric discharge is continued, the electric discharge at the time of the original processing can be immediately switched at the time of the re-processing, and the required laser output can be promptly generated. .

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram of a carbon dioxide gas laser processing machine using the electric shirt method of the present invention. The NC device control unit 1, the discharge power source 3, the carbon dioxide gas laser oscillator 5, the processing table 7, and a pulse with a time width of 50 μs or less are generated. It is composed of a short-time pulse generator 9 and the like.

As shown in the figure, when a machining command (shown by a solid line) is issued from the NC device control section 1 to the discharge power source 3, the discharge power source 3 supplies a predetermined discharge current Pd to the carbon dioxide gas laser oscillator 5 to generate a carbon dioxide gas. The gas laser oscillator 5 outputs laser light Pl. This laser light Pl irradiates and processes the workpiece placed on the processing table 7. When the machining table 7 is moved to complete machining and change the machining position, the NC device controller 1 issues a machining interruption command (indicated by a dotted line) to the short-time pulse generator 9. The short-time pulse generator 9 outputs a pulse signal having a time width of 50 μs or less to the discharging power supply 3, and the discharging power supply 3 supplies the corresponding pulse current Pp to the carbon dioxide laser oscillator 5. In this case, the carbon dioxide gas laser oscillator 5 performs pulse discharge with a time width of 50 μs or less, but does not generate the laser light Pl. In this state, the processing table 7 is moved. Therefore, the work piece is not damaged by the laser light during movement. Processing table 7
When the movement of is completed, the machining is restarted by the machining command.

FIG. 2 shows the discharge current Pd in the above operation,
The time course of the pulse current Pp, the laser light Pl, etc. is shown. As shown in the figure, the laser light Pl is generated by the discharge current Pd during the machining and the machining is performed, but the discharge is continued by the pulse current Pp having the time width of 50 μs or less during the movement of the table, and the output of the laser light Pl is output. It becomes zero.
When the processing is restarted, the laser light Pl is promptly generated by the discharge current Pd and the processing is performed.

[0011]

As can be understood from the above description, the electric shirting method of the laser processing machine according to the present invention has the constructions described in the claims, and therefore, the processing such as waiting and moving of the work piece is performed. At the time of interruption, the laser output can surely be made zero, and the work piece is not damaged by the laser light. Further, when the processing is restarted, the required laser output can be quickly generated. In addition, since a mechanical shirt as in the past is not used, the processing time can be greatly shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of a carbon dioxide gas laser processing machine using the electric shirt method of the present invention.

FIG. 2 is a diagram showing the time course of discharge current Pd, pulse current Pp, laser light Pl, etc. of the carbon dioxide laser processing machine according to the present invention.

[Explanation of symbols]

 Pd Discharge current Pp Pulse current when processing is interrupted Pl Laser output

Claims (1)

[Claims] 1. In a laser processing machine, when the processing is interrupted, the electric discharge of the laser oscillator is 50 μm from the electric discharge during the processing.
A laser processing machine characterized by switching to a pulse discharge of s or less, continuing the discharge and making the laser output zero, switching the pulse discharge to a discharge at the time of processing, and quickly generating a required laser output. Electric shirt method.